J. Nannoplankton Res. 27 (1), 2005, pp.21-95 © 2005 International Nannoplankton Association
ISSN 1210-8049 Printed by Cambridge University Press, UK

21

Palaeogene calcareous nannofossils from the Kilwa andLindi areas of coastal Tanzania (Tanzania Drilling Project
2003-4)
Paul R. Bown
Dept. of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, UK; p.bown@ucl.ac.uk
Manuscript received 21st October, 2004; revised manuscript accepted 2nd February, 2005

Abstract Exceptionally well-preserved and diverse Late Paleocene-Early Oligocene nannofossil assemblages
are described from new onshore drilling sites in southern Tanzania. Hemipelagic claystones, at shallow burial depths,
yield rare but diverse assemblages, characterised by the conspicuous presence of rhabdoliths, pentaliths, pontosphaerids and holococcoliths. Although the presence and diversity of pontosphaerids and holococcoliths is most
likely the result of enhanced preservation, the occurrences of the rhabdoliths and pentaliths may represent a primarily palaeoecological signal, i.e. neritic, warm water. A latest Paleocene origination is confirmed for the
Rhabdosphaeraceae and Pontosphaeraceae, and proposed for the Noelaerhabdaceae. New, transitional coccolith morphologies strongly support an evolutionary link between Zygodiscus and Pontosphaera. Two hundred and sixtyseven taxa are illustrated and 213 described and/or discussed, providing a comprehensive taxonomic review of
Palaeogene calcareous nannofossils. One new family, two new genera, 56 new species, one new subspecies and 10
new combinations are described.

Keywords Paleocene, Eocene, Oligocene, calcareous nannofossils, diversity, taxonomy

1. Introduction
Palaeogene deposits occur in several large patches along
the Tanzanian coast, and the most extensive of these is
between and around the towns of Kilwa and Lindi in thesouth of the country (Figure 1). The predominant lithology is mudstone, with occasional carbonate or siliciclastic
turbidites, although reef limestones and sand-bodies also
occur in parts of the succession (Kent et al., 1971;
Pearson et al., 2004). The area is previously known tomicropalaeontologists, most notably through theforaminiferal work of Blow & Banner (1962), who named
many new species of planktonic foraminifers and typified
several Upper Eocene and Lower Oligocene foraminiferal biozones in the Lindi area. A new research program, theTanzanian Drilling Project (TDP), has recently returned tothis area with the primary aim of recovering pristinelypreserved foraminifera and organic biomarkers for geochemical analysis, in order to improve records of Late
Mesozoic-Palaeogene tropical sea-surface temperaturesand pCO2. The work to date has comprised several fieldseasons (1998-2000) and, more recently, three onshorecoring expeditions (2002-2004). Initial results, including
preliminary microfossil biostratigraphy, lithostratigraphy
and organic geochemistry, are presented in Pearson et al.
(2004, subm.). As well as the primary palaeoclimatological objectives of the project, the material is clearly usefulfor a wide range of micropalaeontological, stratigraphicaland palaeoceanographical purposes, and a team from theUK, Tanzania, Ireland and the US is currently collaborating on this work.
This paper documents and describes the beautifully
preserved and exceptionally diverse Palaeogene calcare-ous nannofossils from the cores recovered during the firsttwo years of drilling, comprising TDP Sites 1-4, 6-8 and
10. Sites 5 and 9 recovered Upper Cretaceous sequenceswith similarly exquisite nannofossil records that will be
published separately (Pearson et al., 2004, subm.; Lees, in
prep.). The taxonomy presented here provides a review
and revision of calcareous nannofossils of the Palaeogene
interval, a time of maximum Cenozoic diversity that saw
the origination of a number of important extant families(Calcidiscaceae, Helicosphaeraceae, Pontosphaeraceae,
Rhabdosphaeraceae) (Bown et al., 2004). A total of 270
species are illustrated, 213 described/discussed, and 60
new taxa are described ,including two new genera and one
new family.
2. Palaeogene
nannofossil study
Much of the early studyof Palaeogene nannofossils was carried out on
epicontinental, hemipelagic sequences, comparable to those of coastal
Tanzania, notably by
Milton N. Bramlette(Bramlette & Riedel,
1954;
Bramlette&
Sullivan, 1961; Bramlette& Wilcoxon, 1967),
Herbert Stradner (e.g.
Stradner, 1958, 1959,
1960, 1962, etc.), Erlend

Dar es
Salaam

Mafia Is.
Cretaceous andPalaeogene outcrop

Kilwa

IndianOceanbasement

Lindi

N
10 km

Figure 1: Location of study area
(after Pearson et al., 2004)

22

Bown

Martini (e.g. Martini, 1958, 1959, 1961, etc.), Frank
Sullivan (Sullivan, 1964, 1965) and Bill Hay (Hay &Mohler, 1967; Hay et al., 1966, 1967). Towards the end of
this period of taxonomic and stratigraphic research, deepsea drilling augmented the earlier onshore data (e.g.
Martini & Bramlette, 1963; Martini, 1965; Gartner, 1971)
and culminated in publication of the standard Cenozoic
nannofossil zonation by Martini (1970, 1971). Since then,much of the focus of Cenozoic calcareous nannofossil
research has shifted from the shelves to the oceans, mostobviously stimulated by the expansion of palaeoceanographic research in the Deep Sea Drilling Project andOcean Drilling Program (ODP). Vast quantities of nannofossil data have been generated by these projects, anddedicated deep-sea biozonations have been formulated,and older schemes subsequently modified by, for example, Bukry (1973, 1975, 1981), Okada & Bukry (1980)and Perch-Nielsen (1985). More recently, interests havefocussed on events of extreme palaeoclimate change, forexample, the Paleocene/Eocene thermal maximum, andboth high-resolution stratigraphic and assemblage data
have resulted (Angori & Monechi, 1996; Aubry, 1996;
Aubry et al., 1996; Schmitz et al., 1997; Bralower, 2002).
Recent syntheses and studies that have included
Paleogene nannofossil taxonomic work include Aubry(1984 et seq.), Perch-Nielsen (1985), Varol (1989),
Bralower & Mutterlose (1995), Bybell & Self-Trail(1995) and de Kaenel & Villa (1996).
The nannofossil assemblages presented here mostclosely resemble those described in the pioneering worksof Stradner, Martini and Bramlette (see above), and differ
significantly from material that is typically recovered in
the deep sea. The Tanzanian material demonstrates theconsiderable difference between Palaeogene assemblagesof the shelves and oceans - in the author’s experience, themost striking differentiation in the history of the group,and for reasons that must include both palaeoecology andtaphonomy. The difference is most clearly demonstrated
by the abundant presence of diverse rhabdoliths, pentaliths, holococcoliths and pontosphaerids, all groups thatare almost completely absent in typical deep-sea sediments. Such differentiation also impacts on the stratigraphic distribution of the fossils and reliability of marker-species, but discussion of the biostratigraphic data isbeyond the scope of this paper, and will be presented elsewhere (but see Pearson et al., 2004, subm.).
3. Material
A total of 10 sites were drilled in 2002 and 2003, eight inthe vicinity of Kilwa (TDP Sites 1-3, 6-10) and two near
Lindi (TDP Sites 4 and 5). Sites were selected to obtain awide spread of sediment ages (Late Cretaceous-Early
Oligocene) in the best-preserved microfossil material possible. Sites were cored using a truck-mounted rig using
water and mud circulation to avoid unnecessary organic
contamination. Cores were 2” (~5cm) in diameter, 3m
long, and cut into sections of 1m. All cores are archived at

the Tanzania Petroleum Development Corporation in Dares-Salaam. Core photographs and VCD sheets arearchived at Cardiff University. Sample identification
numbers are adapted from the procedure used by the ODP.
A typical sample number refers to the site, core number,
section number, and depth in cm from the top of that section. For example, Sample TDP2-27-2, 16-20cm wastaken from TDP Site 2, Core 27, Section 2 between 16 and20cm from the top of that 1m section. The depth of thissample can be calculated by adding 1.16- 1.20m to thedepth from the top of the core (66.70m + 1.16m =67.86m). Additional details concerning the coring andgeological setting can be found in Pearson et al. (2004,
subm.).
4. Methods
Samples were prepared as smear-slides (Bown & Young,1998) and analysed using a Zeiss Axiophot microscope at
x1000 magnification in cross-polarised light (XPL) andphase-contrast (PC). Assemblages were logged semiquantitatively, and slides were observed for at least 30 minutes,
in most cases much longer. Images were captured using
Scion Image software and macros written by Dr. Jeremy
Young (Bown & Young, 1998). For the Palaeogene, theNP biozones of Martini (1971) were used, along with theadditional Middle Eocene subzones of Aubry (1991). The
alternative bioevents used in the Okada & Bukry (1980)
CP biozonation were also considered, where appropriate.
5. Results
Although a relatively broad stratigraphic range of samples
has been studied (Late Paleocene-Early Oligocene), theabundance, diversity, preservation, and even aspects ofassemblage composition, are remarkably consistentthroughout. The nannofossils are invariably rare to few inthe sediments, being significantly diluted by clay and silt
in these predominantly dark green to black claystonelithologies. At some localities nannofossils are moreabundant (e.g. Site TDP2), and occasionally certain horizons are barren. However, preservation of the nannofossils is moderate to excellent, and usually excellent, withdelicate structures, small coccoliths (<3.0µm), holococcoliths and coccospheres consistently present. The quality of the preservation results from both the nature of thesediments, i.e. clay-rich (see Pearson et al., 2001), and thefact that the sediments have never been deeply buried.
The preliminary biostratigraphic results are presented in
Pearson et al. (2004, subm.), and a summary of the zones
and marker-species recognised is given in Figure 2 andTable 1.
5.1 Assemblage composition
The most striking feature of the Tanzanian assemblages is
how greatly they differ from those of the routinely-studied open-ocean. Five groups in particular, the rhabdoliths(Rhabdosphaeraceae: Blackites), pontosphaerids (Pontosphaeraceae), holococcoliths (Clathrolithus, Holodisco-

Palaeogene calcareous nannofossils...Tanzania
Age Ma

Zones
CP
NP

Early Oligocene

2829Marker-species

Mutterlose (1995). As a broad comparison,
Bralower & Mutterlose (1995) described 35
species from levels in Zone NP10 and Subzone
NP15b; equivalent levels from Tanzania yielded 60 and 116, respectively.

1

5.1.1 Braardudosphaeraceae
The abundant, neritic distribution of pentaliths
was noted in some of the earliest Palaeogene
studies (Sullivan, 1964, 1965; Bybell &Gartner, 1972), and the palaeoceanographicalsignificance of this long-ranging taxon has
continued to confound palaeontologists, particularly the anomalous deep-sea ‘braarudosphaerid-chalk’ occurrences (e.g. Kelly etal., 2003). The Early to Middle Eocene saw astriking diversity maximum for this group (18species illustrated here), although it originatedin the earliest Cretaceous and continues to be
represented at present by Braarudosphaera
bigelowii. In the earliest part of this group’s
history, several species of Micrantholithus proliferated on the Early Cretaceous shelves, butthen declined and disappeared in the midCretaceous, and were replaced by much rarer
representatives of Braarudosphaera. Both genera were conspicuous again for a short intervalfollowing the Cretaceous/Tertiary boundary
extinctions. However, in the Late Paleocene to
Eocene, a great diversity of new morphologies
appeared, including anomalously large, heavily-calcified forms (see Plates 34-36), and they
were abundant in shelf settings (e.g. Pemma,
Micrantholithus, Braarudosphaera). Although
the distribution of the group appears to be
restricted to the shelves, the species are represented worldwide, inferring continued genetic
exchange across ocean basins (Bybell &Gartner, 1972). Such exchange is not easily
supported by the fossil record but may be
explained by loss due to preservation, although
it is difficult to see this being the case for suchlarge, robust nannoliths. Their deep-sea
absence may be better explained by ecologicalexclusion, rarity, or the occurrence of life-cycle
stages that are not routinely preserved. Similar
explanations may apply to the other ‘neritic’groups.

LO La. minutus

23

30

FO Sph. distentus

31

TDP sites

FO Sph. ciperoensis

18

17

6

FO He. ethologus (= H. aff. H. carteri)

LO Re. umbilicus >14 m
FO Ch. oamaruensis

37

LO Ch. grandis, Sph. obtusus

38
39

4
14b

17

40

FO Re. stavensis (>10/11 m)

FO Re. bisecta (<10 m)

LO Ch. solitus

LO Sph. furcatolithoides

Middle Eocene

41

14a
16

42

FO Sph. obtusus
FO He. compacta
FO Ret. reticulata
FO Re. umbilicus >14 m

43

13c
15c

44

LO Bl. gladius, Na. fulgens

26

LO Ch. gigas
LO Lo. rotundus
FO Br. serraculoides

45

13b

15b

FO Sph. furcatolithoides

13a

15a

FO Cr. vanheckiae
LO Di. sublodoensis

46

FO Ch. gigas

47
48

FO Na. fulgens

12b

14b

12a

14a

FO Nannotetrina
FO Bl. inflata

49

FO Di. sublodoensis
50

Early Eocene

11

52
53
54

L. Pal.

13
LO T. orthostylus

51

55
56

LO To. callosus
FO T. crassus

10

12

FO Re. dictyoda

FO Di. lodoensis

9b

11

9a

10

FO Sp. radians
FO Sp. conspicuous
LO T. contortus

3

FO T. orthostylus
FO T. contortus

87

FO Rh. bramlettei, Di. diastypus

8b
8a

9

23

FO Rh. cuspis
FO Ca. eodela

10

FO Di. multiradiatus

Figure 2: Nannofossil biostratigraphical schemes for the studied interval (NP and
CP zones of Martini (1971) and Okada & Bukry (1980), respectively). NP zone
markers in large font; species used to date the TDP cores in bold. FO = first evolutionary occurrence; LO = last occurrence. Estimated stratigraphic ranges of the TDP
sections on the right. Time-scale calibrations mostly from Lyle et al. (2002) and
Bralower & Mutterlose (1995)

lithus, Lanternithus, Zygrhablithus, etc.) and pentaliths(Braarudosphaeraceae: Braarudosphaera, Micrantholithus, Pemma) are diverse and common in most of thecores, yet they are rarely observed in oceanic samples,
including those of equivalent latitude, for example, compare with the assemblages illustrated by Bralower &5.1.2 Holococcoliths
Holococcoliths have distinct coccolith architecture, and all extant representatives are small
and prone to immediate post-mortem dissolution in all but
the most favourable taphonomic settings. For example, of
the 86 living holococcolith species, only one or two areseen in Pleistocene sediments (see, e.g., Young, 1998;
Young et al., 2003). It is therefore likely that commonly-

24

Bown

observed fossil holococcoliths represent exceptional, unusually large androbustly constructed morphologies. Even so, mostof these are still only preserved in certain facies,
mostcommonlyinhemipelagic claystones,
and apart from one or two
notableexceptions(Palaeogene Zygrhablithus, Cretaceous Lucianorhabdus), they are never preserved in typical deep-sea
oozes. The preservational
control on Palaeogene
holococcoliths was first
noted by Gartner & Bukry(1969) and is still our best
explanation for their distinct distribution, eventhough there is increasing
evidence of ecologicalcontrols on their extant
Table 1: Age of TDP cores using
distributions (Cros et al.,NP zones of Martini (1971)
2000). The Tanzanianmaterial has yielded 27 holococcolith species (including
two new genera, and 15 new species), doubling the known
Palaeogene diversity, and has revealed extended stratigraphic ranges for many of those previously described.
TDP Core
site
1
1
2-3
5-20
21-22
2
1-9
10-24
26-35
3
1-12
13-19
4
1-7
5
6
1-4
5
6-8
8-9
7A
2-65
33-34
7B
44-51
51-53
1-12
8
9
2-40
10

Age
(NP zone)15
barren23
barren15c
15b
14b/15a11
10/11
17Upper Cret.
barren23
barren
15b
10
10
9b/10
9b
10
Upper Cret.
9b

5.1.3 Rhabdospheraceae
Fossil rhabdoliths are reported as having shelf, rather than
oceanic, distributions (Perch-Nielsen, 1985), based largely on their absence from deep-sea sediments. However, anumber of living species, including Rhabdosphaera clavigera, appear to be widely distributed across both oceans
and marginal seas (Kleijne, 1992). Dissolution may wellinfluence their fossil distribution, as most living rhabdolith species have low preservation potential, and are
rarely seen in Pleistocene sediments (McIntyre &McIntyre, 1971; Roth & Thierstein, 1972; Roth & Berger,
1975; Roth & Coulbourn, 1982; Young et al., 2003).
Eocene rhabdoliths are considerably larger and morerobust than their extant counterparts, and their abundant
neritic distribution may yet prove to be a primary palaeoecological signal. The diverse assemblages from Tanzania
indicate affinities for tropical shelf environments.
The Middle Eocene saw the highest Cenozoic diversity for the Rhabdosphaeraceae, and 27 species are illustrated here, including 11 new species. Like the pentaliths, anumber of these species are globally distributed and usedas marker-taxa, suggesting worldwide connections thatare not obvious from the fossil record.

5.1.4 Pontosphaeraceae
Fossil pontosphaerid coccoliths are generally reported as
typically having shelf distributions, although some arefound more widely (Perch-Nielsen, 1985). Scyphosphaera, in particular, is found only very rarely inCenozoic sediments, and almost always in tropical, neritic settings (Aubry, 1990; Siesser, 1998). Both
Pontosphaera and Scyphosphaera are susceptible to dissolution, despite being rather large and robust coccoliths,
and dissolve in water-depths greater than 3000m (Roth &Berger, 1975; Siesser, 1998). It seems likely that the neritic distribution of fossil pontosphaerids is largely controlled by preservation.
The Middle Eocene saw the Cenozoic diversity maximum for the Pontosphaeraceae, and 23 species are illustrated here.
5.1.5 Cruciplacolithus
Several species of Cruciplacolithus, although rare, arerecorded consistently at most of the Eocene sites, at stratigraphic levels significantly above their previously recorded, predominantly intra-Paleocene, ranges (PerchNielsen, 1985). It seems likely that this group became
largely restricted to the shelves from the Eocene on, hence
their consistent record here, further supported by the neritic distribution of the single living representative,
Cruciplacolithus neohelis (Young et al., 2003).
5.2 Absences
As well as anomalous occurrences, the assemblages
investigated record absences, or rare and infrequent
occurrences, that are also considered notable. Most
importantly, discoasters, which form the basis for much of
the Palaeogene biozonation, are relatively rare despite thetropical setting and their being dissolution-resistant. Suchan observation is unequivocally due to the shelf settingthat excluded or restricted the occurrence of these tropical, oceanic taxa (Aubry, 1984, 1992; Chepstow-Lusty etal., 1992).
The important nannolith marker-species Rhomboaster, Tribrachiatus and Nannotetrina are rare and infrequent, possibly explaining earlier observations concerning their biostratigraphical reliability, but not supporting
the suggestion that they are restricted to nearshore environments (Müller, 1979; Aubry, 1988, 1996).
Representatives of the genus Chiasmolithus are relatively consistently present, but usually rarely, and a number of marker-species are not recorded at all, e.g.
Chiasmolithus solitus (Bramlette & Sullivan, 1961) andChiasmolithus oamaruensis (Deflandre in Deflandre &Fert, 1954). Tanzania was tropical in the Eocene, andthese observations support previous work that suggests
Chiasmolithus was a typically cold- to temperate-water
genus (Wei & Wise, 1992; Persico & Villa, 2004).
5.3 Originations
Finally, the Tanzanian material provides stratigraphic

Palaeogene calcareous nannofossils...Tanzania

constraint on the divergence and origination times ofsome important extant coccolithophore families.
5.3.1 Pontosphaeraceae
Representatives of the Pontosphaeraceae (Pontosphaera
plana) are present in the oldest cores (TDP Site 10) thatare assigned to Subzone NP9b (latest Paleocene), confirming the record of Bramlette & Sullivan (1961).
Notably, they occur alongside species that have features
shared by both Pontosphaera and the older genus
Zygodiscus. Zygodiscus sheldoniae sp. nov., for example,
is Pontosphaera-like (thin, birefringent central-area plate)but has a remnant disjunct bar, demonstrating its
Zygodiscus affinities, and indicating an evolutionary link
between the two genera (Pl.18, figs 25-34). Zygodiscus
clausus shows similar features (Pl.19, figs 1-5). The oldest record of Scyphosphaera in this material is in the
Middle Eocene (NP14b/15a), at the base of TDP Site 2.
5.3.2 Rhabdosphaeraceae
Representatives of the Rhabdosphaeraceae (Blackites herculesii) are present towards the base of TDP Site 7B,
assigned to Subzone NP9b (latest Paleocene - with
Rhomboaster cuspis but prior to the first occurrence ofRhomboaster bramlettei), indicating an origination in thelatest Paleocene.
5.3.3 Calcidiscaceae
A number of ring-shaped Eocene coccoliths have previously been tentatively assigned to the genus Calcidiscus(e.g. Calcidiscus protoannulus), but the Tanzanian material has also yielded more convincing Calcidiscus-likeplacolith coccoliths that are here tentatively assigned to
the genus. Consistent records of Calcidiscus? pacificanus
begin in Zone NP11 (Early Eocene, Site TDP 3). Anothercommon coccolith, here tentatively assigned to the
Neogene genus Umbilicosphaera (U.? jordanii sp. nov.),
is also recorded from the Late Paleocene (NP9b, TDP Site
10).
5.3.4 Noelaerhabdaceae
Circular, birefringent placolith coccoliths, reminiscent ofyounger Cyclicargolithus coccoliths, are recorded from
Subzone NP9b (latest Paleocene) and named
Cyclicargolithus luminis. Electron microscope observation is required to substantiate their generic affinities but
they may prove to be the oldest representatives of thisfamily group.
6. Systematic palaeontology
There follows a comprehensive taxonomic review of the
Tanzanian nannofossil assemblages. All recorded taxa arelisted and illustrated, and remarks and short descriptions
are provided for new taxa and taxa that require clarification or are taxonomically problematic. Descriptive terminology follows the guidelines of Young et al. (1997). The
plates comprise ~1400 images of the 270 species encoun-25

tered, and multiple images attempt to represent the rangeof morphological variation. All images are at the same
magnification (x2180). The layout of the taxonomy andplates, and much of the higher taxonomic rationale, follows the recently-published guide to extant coccolithophore taxonomy (Young et al., 2003), together withthe earlier review of Cenozoic taxonomy by Young and
Bown (1997). Range information is given for stratigraphic distributions at the Tanzanian sites. Additional stratigraphical data are given when taxa have well-establishedranges, or where such information is deemed relevant.
Morphometric data are given for all new taxa and elsewhere where appropriate. Only bibliographic references
not included in Perch-Nielsen (1985) and Bown (1998)
are included in the reference list.
The following abbreviations are used: LM - lightmicroscope, XPL cross-polarised light, PC - phase-contrast illumination; FO - first occurrence, LO - last occurrence; L - length, W - width, H - height, CW - coccolith
width, SW - spine width. Type material and electronic
images are stored in the Department of Earth Sciences,
UCL.
6.1 Placolith coccoliths
Order ISOCHRYSIDALES Pascher, 1910
Family PRINSIACEAE Hay & Mohler, 1967 emend.
Young & Bown, 1997
Toweius callosus Perch-Nielsen, 1971
Pl.1, figs 1-5
Toweius eminens (Bramlette & Sullivan, 1961) PerchNielsen, 1971
Pl.1, figs 6-10
Toweius occultatus (Locker, 1967) Perch-Nielsen, 1971
Pl.1, figs 11-13
Toweius pertusus (Sullivan, 1965) Romein, 1979
Pl.1, figs 14-17, 21-25
Toweius serontinus Bybell & Self-Trail, 1995
Pl.1, figs 18-20. Medium to large (6-8µm), broadly elliptical, with wide, birefringent central-area plate, pierced by
10-20 small pores. Occurrence: NP9b-10; TDP Sites 7A,
7B.
Toweius sp.1
Pl.1, figs 26-27. Medium to large (6-8µm), circular, withrelatively narrow central-area (less than width of shields)
crossed by finely-perforate plate clearly visible in XPL.
Shield and tube-cycle distinctly bright in XPL.
Occurrence: NP9b-10; TDP Sites 7A, 7B.
Toweius sp.2
Pl.1, figs 28-30. Medium-sized (4-7µm), elliptical-subcircular, with relatively wide central-area (approximately
equal to width of shields) crossed by (finely-perforate?)
plate visible in XPL. Occurrence: NP10-11; TDP Sites 3,

26

Bown

7A.
Toweius rotundus Perch-Nielsen in Perch-Nielsen et al.,1978
Pl.1, figs 31-32. Small (~<4µm), subcircular-circular,
with narrow central-area spanned by (perforate?) plate.
Occurrence: NP11; TDP Site 3; Varol (1989).
Prinsius martinii (Perch-Nielsen, 1969) Haq, 1971
Pl.1, fig.33
Hornibrookina arca Bybell & Self-Trail, 1995
Pl.1, figs 34-35
Family NOELAERHABDACEAE Jerkovic, 1970
emend. Young & Bown, 1997
Differentiation of the genera Reticulofenestra andCyclicargolithus is problematical in this material because
many of the reticulofenestrid coccoliths are subcircularwith high tube-cycles and central-areas of variable width.
Cyclicargolithus is used here for coccoliths that are predominantly circular with central-areas narrower than thewidth of the shields.
Cyclicargolithus luminis (Sullivan, 1965) Bukry, 1971
Pl.2, figs 1-2. Small- to medium-sized (3.0-4.5µm), circular coccoliths with birefringent shields and small, central
hole. Occurrence: NP9b/10-11; TDP Sites 3, 7A, 7B, 8.
Cyclicargolithus floridanus (Roth & Hay in Hay et al.,1967) Bukry, 1971
Pl.2, figs 3-10. Small to large, subcircular reticulofenestrid coccoliths with high tube-cycle and narrow, vacantcentral-area. Great variability in size; smaller morphologies (<5µm) were logged separately. Occurrence:
NP14b-23; TDP Sites 1, 2, 4, 6.
Reticulofenestra minuta Roth, 1970
Pl.2, figs 11-12
Reticulofenestra dictyoda (Deflandre in Deflandre &Fert, 1954) Stradner in Stradner & Edwards, 1968
Pl.2, figs 13-19. Name applied to all elliptical reticulofenestrid coccoliths <14µm, with relatively wide, vacant central-area (e.g. Bralower & Mutterlose, 1995). Informallygrouped into small (<3µm: Reticulofenestra minuta),medium (3-5µm), large (5-7µm) and very large (7-14µm).
Reticulofenestra umbilicus was reserved for those specimens >14µm, and seen only rarely.
Reticulofenestra umbilicus (Levin, 1965) Martini &Ritzkowski, 1968
Pl.2, fig.20
Reticulofenestra wadeae sp. nov.
Pl.2, figs 21-25. Derivation of name: After Dr. Bridget
Wade (Univ. of Cardiff, UK), micropalaeontologist.
Diagnosis: Medium- to large-sized, subcircular retic-

ulofenestrid coccoliths with wide central-area (equal towidth of shields) and no visible net or grill in LM.
Differentiation: Subcircular outline distinguishes thisspecies from most other reticulofenestrids, and the central
area is wider than in Cyclicargolithus. Central-area wider
than in Reticulofenestra circus de Kaenel & Villa, 1996,
and smaller than in Reticulofenestra hillae Bukry &Percival, 1971. Dimensions: L = 5.8-10.3µm. Holotype:
Pl.2, fig.23. Paratype: Pl.2, fig.24. Type locality: TDP
Site 2, Kilwa Masoko, Tanzania. Type level: Middle
Eocene, Sample TDP2-15-1, 89cm (Subzone NP15b).
Occurrence: NP15b-c; TDP Site 2.
Reticulofenestra bisecta (Hay et al., 1966) Roth, 1970
Pl.2, figs 27-28. Used for reticulofenestrid coccoliths witha central plug that are >10µm (NB the holotype is ~8µm).
Reticulofenestra stavensis (Levin & Joerger, 1967)
Varol, 1989
Pl.2, figs 29-30. Used for reticulofenestrid coccoliths witha central plug that are >10µm (NB the holotype is~14µm). Synonym: Reticulofenestra scrippsae (Bukry &Percival, 1971) Roth, 1973 (holotype L = 9.5µm).
Reticulofenestra reticulata (Gartner & Smith, 1967)
Roth & Thierstein, 1972
Pl.2, figs 31-34
Reticulofenestra lockeri Müller, 1970
Pl.2, fig.35; Pl.3, figs 1-5. Elliptical reticulofenestrids
with weakly birefringent central-area nets are included inthis species. Occurrence: NP17-23; TDP Sites 1, 4, 6.
Order COCCOSPHAERALES Haeckel, 1894 emend.
Young & Bown, 1997
Family COCCOLITHACEAE Poche, 1913 emend.
Young & Bown, 1997
Coccolithus pelagicus (Wallich, 1877) Schiller, 1930
Pl.3, figs 6-7; Pl.4, fig.1
Coccolithus cachaoi sp. nov.
Pl.3, figs 8-10. Derivation of name: After Dr. MárioCachão (Univ. of Lisbon, Portugal), nannopalaeontologist. Diagnosis: Medium- to large-sized, elliptical
Coccolithus coccoliths with narrow central-area spannedby broad, transverse, disjunct bar. Remarks: Some
Neogene-Holocene Coccolithus pelagicus coccoliths
have a central-area bar but are not given separate species
status. The specimens observed here are considered distinct enough to warrant separate status. Dimensions: L =8.7µm. Holotype: Pl.3, fig.8 (fig.9 same specimen).
Paratype: Pl.3, fig.10. Type locality: TDP Site 2, Kilwa
Masoko, Tanzania. Type level: Middle Eocene, Sample
TDP2-28-1, 50cm (Subzone NP15a). Occurrence:
NP14b/15a-15b; TDP Sites 2, 6.

Palaeogene calcareous nannofossils...Tanzania

Coccolithus eopelagicus (Bramlette & Riedel, 1954)
Bramlette & Sullivan, 1961
Pl.3, fig.11
Coccolithus minimus sp. nov.
Pl.3, figs 12-15. Derivation of name: From minimus,
meaning smallest, and referring to the size of this coccolith. Diagnosis: Small (<5µm), circular Coccolithus coccoliths with narrow, open central-area. Differentiation:
Smaller than other circular Coccolithus coccoliths.
Dimensions: L = 3.3-4.7µm. Holotype: Pl.3, fig.13(fig.12 same specimen). Paratype: Pl.3, fig.14 (fig.15
same specimen). Type locality: TDP Site 7A,
Kwamatola, Tanzania. Type level: Lower Eocene,
Sample TDP7A-65-1, 70cm (Zone NP10). Occurrence:
NP9b-15c; TDP Sites 2, 3, 6, 7A, 7B, 10.
Coccolithus formosus (Kamptner, 1963) Wise, 1973
Pl.3, figs 16-18; Pl.4, fig.2
Coccolithus crucis sp. nov.
Pl.3, figs 19-25. Derivation of name: From crucis, meaning cross, referring to the cross-bars that characterise thiscoccolith. Diagnosis: Large, circular Coccolithus coccoliths with narrow central-area spanned by thin cross-bars.
Remarks: May represent intraspecific variation or apreservational morphotype of Coccolithus formosus.
Differentiation: Like C. formosus but possessing centralarea cross-bars. Dimensions: L = 8.5-9.7µm. Holotype:
Pl.3, fig.21 (fig.22 same specimen). Paratypes: Pl.3,
fig.23; Pl.3, fig.25 (fig.24 same specimen). Type locality:
TDP Site 2, Kilwa Masoko, Tanzania. Type level: Middle
Eocene, Sample TDP2-2-1, 15cm (Subzone NP15c).
Occurrence: NP14b/15a-17; TDP Sites 2, 4, 6.
Coccolithus foraminis sp. nov.
Pl.3, figs 26-30. Derivation of name: From foraminis,
meaning opening, referring to the open central-area thatcharacterises this coccolith. Diagnosis: Large, subcircular
Coccolithus coccoliths with wide, vacant central-area(less than or equal to width of shields). Differentiation:
Like C. formosus but subcircular and with a wider centralarea. Dimensions: L = 7.8-9.4µm. Holotype: Pl.3, fig.27(fig.26 same specimen). Paratype: Pl.3 fig.29 (fig.30
same specimen). Type locality: TDP Site 7A,
Kwamatola, Tanzania. Type level: Upper Paleocene,
Sample TDP7A-65-1, 70cm (Zone NP10). Occurrence:
NP10; TDP Site 7A.
Coccolithus latus sp. nov.
Pl.3, figs 31-35. Derivation of name: From latus, meaning broad or wide, referring to the wide central-area thatcharacterises this coccolith. Diagnosis: Medium to large,
elliptical Coccolithus coccoliths with wide (greater thanwidth of shields), vacant central-area. Differentiation:
Like C. formosus and C. foraminis but elliptical, and witha wider central-area. Dimensions: L = 6.8-8.1µm.

27Holotype: Pl.3, fig.33 (fig.32 same specimen). Paratype:
Pl.3, fig.34 (fig.35 same specimen). Type locality: TDP
Site 3, Mpara Hill, Tanzania. Type level: Lower Eocene,
Sample TDP3-4-3, 52cm (Zone NP11). Occurrence:
NP10/11-11; TDP Site 3.
Coccolithus mutatus (Perch-Nielsen, 1971) comb. nov.
Pl.4, figs 3-8. Basionym: Cruciplacolithus mutatus
Perch-Nielsen, 1971, p.23, pl.15, fig.2; Det Kongelige
Danske Videnskabernes Selskab Biologiske Skrifter, 18: 176. Remarks: Very large (>14µm) Coccolithus with wide
central-area and narrow, axial to slightly rotated crossbars. Probably included in the Chiasmolithus gigas concept of Bramlette & Sullivan (1961). Not widely recorded since its first description.
The classification of Eocene Coccolithaceae coccoliths is problematical because of the presence of centralarea cross-bars across generic groupings that are supposedly defined by the presence or absence of such bars, orparticular orientations of bars. This species is included in
Coccolithus because of the appearance of its rim (see also
Coccolithus staurion). Dimensions: L = 14.8-19.2µm.
Occurrence: NP14b/15a-15c; TDP Site 2.
Coccolithus staurion Bramlette & Sullivan, 1961
Pl.4, figs 9-13. Remarks: Large Coccolithus with narrow
central-area and axial cross-bars. Dimensions: L = 7.615.0µm. Occurrence: NP10-15c; TDP Sites 2, 6, 7A, 7B,
8. Synonym: Ericsonia insolita Perch-Nielsen, 1971.
Ericsonia Black, 1964
Used here for circular, Coccolithus-like coccoliths thathave broad upper tube-elements that dominate the distal
shield. The dominance of the R-unit cycle results in abright LM XPL image but the darker distal shield is seenclearly in PC.
Ericsonia subpertusa Hay & Mohler, 1967
Pl.4, figs 19-23. Ericsonia coccoliths with narrow, vacantcentral-area, usually narrower than the shields.
Occurrence: NP9b; TDP10. Lower-Upper Paleocene(Perch-Nielsen, 1985).
Ericsonia robusta (Bramlette & Sullivan, 1961) Edwards& Perch-Nielsen, 1975
Pl.4, figs 24-29. Narrow rim with wide, vacant centralarea that is wider than the shields. Large size-range (3.69.8µm, this work). Occurrence: NP9b; TDP10. LowerUpper Paleocene (Perch-Nielsen, 1985).
Ericsonia staerkeri sp. nov.
Pl.4, figs 30-33. Derivation of name: After Scott
Staerker, nannopalaeontologist (BP-Amoco, Houston,
USA). Diagnosis: Small (<5.0µm), circular placolithdominated by a birefringent cycle in XPL, and with relatively wide central-area (just greater than shields)
spanned by thin cross-bars. Differentiation: Similar to E.

28

Bown

robusta but smaller and with a central cross-structure.
Dimensions: L = 4.1-4.3µm. Holotype: Pl.4, fig.31 (figs
30, 32 same specimen). Paratype: Pl.4, fig.33. Type
locality: TDP Site 3, Mpara Hill, Tanzania. Type level:
Lower Eocene, Sample TDP3-2-2, 64cm (Zone NP11).
Occurrence: NP11; TDP Site 3. Rare.
Campylosphaera dela (Bramlette & Sullivan, 1961) Hay& Mohler, 1967
Pl.5, figs 1-10. Narrow, arched placoliths with axial crossbars. High degree of variability in size (5-10µm) and outline, but do not fall easily into separate classes. There arebroad trends in increasing size and increasing ‘squareness’ of outline, but I was unable to systematically differentiate Campylosphaera eodela Bukry & Percival, 1971
(smaller, more elliptical?) from Campylosphaera dela. In
any case, the holotypes of the two species are extremely
similar. The two names are used on Plate 5 only as an
attempt to illustrate variations in morphology.
Occurrence: NP9b-17; TDP Sites 2, 3, 4, 6, 7A, 7B, 8,
10.
Campylosphaera eroskayi (Varol, 1989) comb. nov.
Pl.5, figs 11-14. Basionym: Clausicoccus eroskayi Varol,
1989, pp.290-291, pl.2, fig.9; Rev. Española deMicropaleont., XXI: 273-320. Small- to medium-sized(~4-6µm), Campylosphaera-like, broadly elliptical placolith (dark shields in XPL), with very narrow centralarea filled with broad cross-bars. Occurrence: NP9b/1010; Sites 7A, 7B.
Campylosphaera sp.2
Pl.5, figs 15-17. Medium to large (6.6-9.7µm), ellipticalto oblong Campylosphaera with narrow central-areafilled with broad cross-bars. Occurrence: NP9b/10-10;
Sites 3, 7A, 7B, 8.
Cruciplacolithus Hay & Mohler in Hay et al., 1967
Generally considered a Paleocene genus (Perch-Nielsen,1985) but consistently present, though typically rare, in
the Early-Middle Eocene of the Tanzanian sections. The
closely allied genera Campylosphaera and Bramletteius
are also often common components of these assemblages.
Cruciplacolithus primus Perch-Nielsen, 1977
Pl.5, figs 18-19, 21, 24
Cruciplacolithus cf. C. primus Perch-Nielsen, 1977
Pl.5, figs 20, 22-23
Cruciplacolithus asymmetricus van Heck & Prins, 1987
Pl.5, figs 25-26
Cruciplacolithus edwardsii Romein, 1979
Pl.5, figs 27-29
Cruciplacolithus frequens (Perch-Nielsen, 1977)
Romein, 1979
Pl.5, figs 30-32
Cruciplacolithus latipons Romein, 1979
Pl.5, figs 33-35; Pl.7, fig.16

Cruciplacolithus? cassus sp. nov.
Pl.6, figs 1-3. Derivation of name: From cassus, meaning empty, and referring to the apparent lack of structuresin the central-area of this coccolith. Diagnosis: Bicyclic
placolith with dark outer-cycle, slightly brighter innercycle and relatively wide central-area (approximately
same width as shields). No central structures observed.
Dimensions: L = 6.5µm Holotype: Pl.6, fig.1. Paratype:
Pl.6, fig.2. Type locality: TDP Site 7A, Kwamatola,
Tanzania. Type level: Lower Eocene, Sample TDP7A-21, 10cm (Zone NP10). Occurrence: NP10-11; TDP Sites
3, 7A.
Cruciplacolithus cruciformis (Hay & Towe, 1962) Roth,1970
Pl.6, figs 4-10. Large (6-10µm), with narrow shields andaxial to diagonal cross-bars. Occurrence: NP15a-17;
TDP Sites 2, 4.
Bramletteius serraculoides Gartner, 1969
Pl.6, figs 11-15
Chiasmolithus bidens (Bramlette & Sullivan, 1961) Hay& Mohler, 1967
Pl.6, figs 16-20
Chiasmolithus consuetus (Bramlette & Sullivan, 1961)
Hay & Mohler, 1967
Pl.6, figs 21-25
Chiasmolithus nitidus Perch-Nielsen, 1971
Pl.6, figs 26-30
Chiasmolithus gigas (Bramlette & Sullivan, 1961)
Radomski, 1968
Pl.6, figs 31-35; Pl.7, figs 1-3
Chiasmolithus grandis (Bramlette & Riedel, 1954)
Radomski, 1968
Pl.7, figs 4-11
Clausicoccus Prins, 1979
Used here for Cruciplacolithus-like coccoliths that havecentral-areas spanned by narrow (Clausicoccus subdistichus), broad (Clausicoccus fenestratus [syn. C. cribellum Bramlette & Sullivan, 1961]) or very broad(Clausicoccus vanheckiae) perforate plates. The species
latipons is retained within Cruciplacolithus because of
the clear nature of the cross, which nevertheless fills thecentral area.
Clausicoccus subdistichus (Roth & Hay in Hay et al.,1967) Prins, 1979
Pl.7, figs 12-15
Clausicoccus fenestratus (Deflandre & Fert, 1954) Prins,
1979
Pl.7, figs 17-21
Clausicoccus vanheckiae (Perch-Nielsen, 1986) deKaenel & Villa, 1996
Pl.7, figs 22-26
Family CALCIDISCACEAE Young & Bown, 1997
Elliptical, subcircular and circular coccoliths with non-Palaeogene calcareous nannofossils...Tanzania

birefringent distal shields and narrow or closed centralareas. The Eocene specimens illustrated here are comparable in LM appearance to Neogene Calcidiscus coccoliths, hence the generic assignment below. However, further morphological analysis (in train) is necessary before
this relationship can be confirmed.
6.1.1 Narrow-rimmed, circular/ringshaped placoliths?Family CALCIDISCACEAE Young & Bown, 1997
Coronocyclus bramlettei (Hay & Towe, 1962) comb.
nov.
Pl.8, figs 1-7. Basionym: Cyclolithus bramlettei Hay &Towe, 1962, p.500, pl.5, fig.6; pl.7, fig.2; Eclog. Geol.
Helv., 55: 497-517. Remarks: Small to medium (3.57.5µm), ring-shaped coccoliths, distinctly bicyclic in
XPL. The two cycles are similar in width; the bright innercycle is crossed by non-axial extinction lines.
Differentiation: Like Coronocyclus nitescens but smaller(<7.5µm) and more distinctly bicyclic in XPL.
Occurrence: NP9b-17; TDP Sites 2, 3, 4, 7A, 7B, 8.
Coronocyclus nitescens (Kamptner, 1963) Bramlette &Wilcoxon, 1967
Pl.8, figs 8-15. Large (>7.5µm), ring-shaped coccoliths,
bicyclic in XPL. The birefringent cycle dominates the
XPL image and is crossed by extinction lines that are nonaxial. Outer edge typically serrated. Occurrence: NP1723. LO NN6 (Young, 1998).
Umbilicosphaera? jordanii sp. nov.
Pl.8, figs 16-24. Derivation of name: After Dr. Ric
Jordan, nannoplankton (palaeo)biologist. Diagnosis:
Medium-sized (3.5-6.0µm), circular, ring-shaped placoliths with non-birefringent distal shield, narrow, brighttube-cycle crossed by non-axial extinction lines, andvacant central-area that is slightly wider than the shields.
Differentiation: Broader shields than C. bramlettei and
C. nitescens. Comparable in general morphology to C.?
protoannulus, but lower-birefringent shield appearance
and bright tube-cycle is less well defined in XPL. In addition, the extinction lines crossing the tube-cycle are nearaxial in C.? protoannulus and near-diagonal in U.? jordanii. Dimensions: L = 2.4-2.8µm. Holotype: Pl.8, fig.18(fig.19 same specimen). Paratype: Pl.8, fig.20. Type
locality: TDP Site 8, Singino Hill, Tanzania. Type level:
Lower Eocene, Sample TDP8-1-1, 30cm (Zone NP10).
Occurrence: NP9b-23; TDP Sites 1, 8, 7A, 7B, 10.
Calcidiscus? protoannulus (Gartner, 1971) Loeblich &Tappan, 1978
Pl.8, figs 25-30. Small- to medium-sized (4.5-8.0µm),
ring-shaped coccoliths that are distinctly bicyclic in XPL;
bright inner-cycle narrower than outer cycle, and crossedby extinction lines that are near-axial. Occurrence:

29

NP15b-23; TDP Sites 1, 2, 6.
Calcidiscus? pacificanus (Bukry, 1971) Varol, 1989
Pl.9, figs 1-10. Medium to large (6-9µm), circular-subcircular placoliths with closed central-area. Shield elements
clearly visible, and proximal shield typically significantly
smaller than distal. Occurrence: NP11-15c; TDP Sites 2,
3.
Calcidiscus bicircus sp. nov.
Pl.9, figs 11-23. Derivation of name: From bi, meaning
two, and circus, meaning ring, referring to the bicyclic
appearance of this coccolith. Diagnosis: Medium to large(5-9µm), circular-subcircular placoliths with non-birefringent distal shield and narrow to closed central-areasurrounded by narrow, bright tube-cycle. Differentiation:
Like C.? pacificanus but with bright inner tube-cycle.
Dimensions: L = 5.1-8.2µm. Holotype: Pl.9, fig.11(fig.12 same specimen). Paratype: Pl.9, fig.14 (fig.15
same specimen). Type locality: TDP Site 2, Kilwa
Masoko, Tanzania. Type level: Middle Eocene, Sample
TDP2-26-1, 15cm (Subzone NP15c). Occurrence:
NP15a-17; TDP Sites 2, 4, 6.
Calcidiscus? parvicrucis sp. nov.
Pl.9, figs 24-28. Derivation of name: From parvus,
meaning small, and crucis, meaning cross, referring to thesmall cross-bars that characterise this coccolith.
Diagnosis: Medium-sized (5-6µm), circular-subcircular
placoliths with non-birefringent distal shield, narrow,bright tube-cycle, and narrow central-area spanned bysmall, axial cross. Differentiation: Like C.? bicircus butwith a small, axial cross. Dimensions: L = 5.0-6.2µm.
Holotype: Pl.9, fig.24 (fig.25 same specimen). Paratype:
Pl.9, fig.26. Type locality: TDP Site 7A, Kwamatola,
Tanzania. Type level: Lower Eocene, Sample TDP7A-262, 35cm (Zone NP10). Occurrence: NP10-11; TDP Site
3, 7A, 8.
Calcidiscus? henrikseniae sp. nov.
Pl.9, figs 31-34. Derivation of name: After Karen
Henriksen (Univ. of Copenhagen, Denmark), nannoplankton palaeobiologist and biomineralogist. Diagnosis:
Medium-sized (6-7µm), elliptical placolith with non-birefringent distal shield, and vacant central-area approximately same width as shields. Dimensions: L = 6.17.0µm. Holotype: Pl.9, fig.33 (fig.34 same specimen).
Paratype: Pl.9, fig.31 (fig.32 same specimen). Type
locality: TDP Site 2, Kilwa Masoko, Tanzania. Typelevel: Middle Eocene, Sample TDP2-4-1, 50cm (Subzone
NP15c). Occurrence: NP15b-c; TDP Site 2.
Calcidiscus? cf. C.? henrikseniae sp. nov.
Pl.9, figs 29-30. Like C.? henrikseniae but circular.

30

Bown

6.1.2 Placolith coccoliths incertae sedis
Hayella situliformis Gartner, 1969
Pl.10, figs 6-9
Hayella? gauliformis Troelsen & Quadros, 1971
Pl.10, fig.35
Tetralithoides symeonidesii Theodoridis, 1984
Pl.10, figs 11-12. Dark, elliptical coccoliths with centralarea filled by four dark blocks joined along diagonal
sutures. Not previously recorded in sediments older than
Miocene (Young, 1998). Occurrence: NP15b-c; TDP
Sites 2, 6.
Pedinocyclus larvalis Bukry & Bramlette, 1971
Pl.10, fig.14
Ellipsolithus anadoluensis Varol, 1989
Pl.10, figs 16-23. Rather inconspicuous Ellipsolithus
species, with XPL image dominated by highly-birefringent tube-cycle; no central-area structure visible. Most
commonly and continuously occurring Ellipsolithus in the
Tanzanian sections. Occurrence: NP9b-11; TDP Sites 3,
7A, 7B, 8, 10
Ellipsolithus bollii Perch-Nielsen, 1977
Pl.10, figs 24-25
Ellipsolithus distichus (Bramlette & Sullivan, 1961)
Sullivan, 1964
Pl.10, figs 26-28
Ellipsolithus macellus (Bramlette & Sullivan, 1961)
Sullivan, 1964
Pl.10, figs 29-30
Ilselithina fusa Roth, 1970
Pl.20, fig. 30
6.2 Murolith coccoliths
6.2.1 Mesozoic survivor muroliths
Order EIFFELLITHALES Rood et al., 1971
Family CHIASTOZYGACEAE Rood et al., 1973
Jakubowskia leoniae Varol, 1989
Pl.11, figs 1-3. Elliptical with narrow rim and wide,
vacant central-area. Occurrence: NP9b-11; TDP Sites 3,
7A, 7B, 8, 10. Rare. NP12 (Varol, 1989).
Neocrepidolithus grandiculus sp. nov.
Pl.11, figs 4-6. Derivation of name: From grandiculus,
rather large, referring to the size of this species.
Diagnosis: Medium to large murolith-coccolith withbroad rim, unicyclic in XLP, and narrow, vacant centralarea. The central-area width is variable, usually aroundthe same width as the rim, but may be narrower or closed.
Differentiation: Similar in morphology to the Jurassic
species Crepidolithus crassus Deflandre, 1954, and distinguished from other Palaeogene Neocrepidolithus

species by its larger size, open central-area, and simple,
unicyclic rim-image. Dimensions: L = 7.0-13.5µm; W =6.0-10.0µm. Holotype: Pl.11, fig.4. Paratypes: Pl.11,
fig.5; Pl.11, fig.6. Type locality: TDP Site 7B,
Kwamatola,
Tanzania.
Typelevel:
Upper
Paleocene/Lower Eocene, Sample TDP7B-51-1, 20cm
(Zone NP9b/10). Occurrence: NP9-11; TDP Sites 3, 7A,
7B, 8, 10.
Zeugrhabdotus sigmoides (Bramlette & Sullivan, 1961)
Bown & Young, 1997
Pl.11, figs 7-10
Staurolithites primaevus sp. nov.
Pl.11, figs 11-15. Derivation of name: From primaevus,
young or youthful, and referring to the age of this coccolith. Diagnosis: Small (<4µm), elliptical muroliths withnarrow, bicyclic rim, and narrow central-area spanned bysmall, axial cross. Differentiation: Similar to Mesozoic
Staurolithites species but the only Cenozoic representative currently recognised; characterised by its small sizeand compact morphology. Dimensions: L = 3.2-3.6µm;
W = 3.3-3.9µm. Holotype: Pl.11, fig.12 (fig.13 same
specimen). Paratype: Pl.11, fig.14. Type locality: TDP
Site 7B, Kwamatola, Tanzania. Type level: Lower
Eocene, Sample TDP7A-50-1, 30cm (Zone NP9b/10).
Occurrence: NP9b/10-11; TDP Sites 3, 7A, 7B, 8.
6.2.2 Cenozoic muroliths
Order ZYGODISCALES Young & Bown, 1997
Family HELICOSPHAERACEAE Black, 1971
Genus Helicosphaera Kamptner, 1954
Helicosphaera compacta Bramlette & Wilcoxon, 1967
Pl.11, figs 16-25. Elliptical with well-defined birefringent
blanket in XPL and narrow central-area spanned by conjunct bar. Occurrence: NP17-23; TDP Sites 1, 4,
Helicosphaera clarissima sp. nov.
Pl.11, figs 26-35. Derivation of name: The superlative of
clarus, meaning clear, bright, or distinct, and referring to
the LM appearance of this coccolith. Diagnosis: Ellipticalto almond-shaped Helicosphaera with well-defined birefringent blanket in XPL and central-area spanned bybroad, oblique, disjunct, birefringent bar. Differentiation:
Like H. compacta but with a disjunct bar; similar to
Helicosphaera heezenii Bukry, 1971 but the latter has alongitudinal bar that fills the central-area. Dimensions: L= 7.5-11.5µm. Holotype: Pl.11, fig.33 (fig.34 same specimen). Paratype: Pl.11, fig.30. Type locality: TDP Site 4,near Ras Tipuli, Tanzania. Type level: Middle Eocene,
Sample TDP4-1-3, 60cm (Zone NP17). Occurrence:
NP17; TDP Site 4.

Palaeogene calcareous nannofossils...Tanzania

31

Helicosphaera lophota (Bramlette & Sullivan, 1961)
Locker, 1973
Pl.12, figs 1-10. Elliptical, oblong or reniform with wide
flange and central-area spanned by broad, near-longitudinal, disjunct bar with a distinct median suture.
Occurrence: NP15b-c; TDP Sites 2, 6.

Helicosphaera obliqua Bramlette & Wilcoxon, 1967
Pl.13, figs 23-27. Elliptical to oblong with a wing that
ends in a spur, and two oblique slits that cross the centralarea. Occurrence: NP23; Site TDP6. NP23-NN6 (Young,1998). Synonym: Helicosphaera perch-nielseniae Haq,
1971.

Helicosphaera reticulata Bramlette & Wilcoxon, 1967
Pl.12, figs 11-15

Helicosphaera recta Haq, 1966 (Jafar & Martini, 1975)
Pl.13, figs 28-30

Helicosphaera seminulum Bramlette & Sullivan, 1961
Pl.12, figs 16-25. Elliptical with relatively wide centralarea spanned by broad, transverse to slightly oblique, disjunct bar. Probably intergrades with Helicosphaera bramlettei. Occurrence: NP15b-23; TDP Sites 1, 2, 4, 6.

Family PONTOSPHAERACEAE Lemmermann, 1908

Helicosphaera bramlettei (Müller, 1970) Jafar &Martini, 1975
Pl.12, figs 26-35. Elliptical with relatively wide centralarea spanned by broad, oblique, disjunct bar.
Occurrence: NP15b-23; TDP Sites 1, 2, 4, 6.
Helicosphaera wilcoxonii (Gartner, 1971) Jafar &Martini, 1975
Pl.13, figs 1-5. Like H. seminulum but with a flange that
ends in a spur. Occurrence: NP17; TDP Site 4.
Helicosphaera sp.2
Pl.13, figs 6-10. Almond-shaped helicoliths with nearlongitudinal, disjunct bar that is dark at 0° in XPL.
Occurrence: NP15b; TDP Site 6.
Helicosphaera sp.3
Pl.13, figs 11-15. Elliptical helicoliths with broad, disjunct bar filling central-area. Occurrence: NP17; TDP
Site 4.
Helicosphaera ethologa sp. nov.
Pl.13, figs 16-22. Derivation of name: From ethologus,
meaning mimic, and referring to the similarity between
this coccolith and the younger Helicosphaera carteri.
Diagnosis: Large helicoliths with a flange ending in awing. Rather diffuse blanket image in XPL, and closed
central-area or with two narrow, near-longitudinal slits.
Differentiation: Very similar to the Neogene
Helicosphaera carteri, hence the previous informal designation as Helicosphaera aff. H. carteri by de Kaenel &Villa (1996). Stratigraphic range is distinctly different andthe wing is somewhat less strongly developed.
Dimensions: L = 10.1-11.2µm. Holotype: Pl.13, fig.18(figs 16, 17 same specimen). Paratype: Pl.13, fig.19(fig.20 same specimen). Type locality: TDP Site 1, Kilwa
Masoko, Tanzania. Type level: Lower Oligocene, Sample
TDP1-14-1, 80cm (Zone NP23). Occurrence: NP23;
TDP Site 1. NP23-24 (de Kaenel & Villa, 1996).

Genus Pontosphaera Lohmann, 1902
Used here for all low-rimmed pontosphaerid coccoliths(cribriliths of some authors), including those with welldefined bridges that are classified as Transversopontis bysome authors. Divided informally into two groups, differentiated on the presence or absence of plate ornamentation.
Pontosphaera plana group
Pontosphaerids with plain, unornamented rims and plates.
Pontosphaera plana (Bramlette & Sullivan, 1961) Haq,
1971
Pl.14, figs 1-6. Simple, unadorned plate, typically with
two narrow, longitudinal slits. Pontosphaera inconspicua(Sullivan, 1964) was used for small, early specimens.
Occurrence: NP9b-17; TDP Sites 2, 3, 4, 7A, 7B, 8, 10.
Pontosphaera versa (Bramlette & Sullivan, 1961)
Sherwood, 1974
Pl.14, figs 7-13. Simple, unadorned plate, typically with
two longitudinal slits, and a broad raised margin/rim.
Occurrence: NP10-23; TDP Sites 2, 3, 4, 6, 7A, 7B, 8.
Synonym: Pontosphaera scissura (Perch-Nielsen, 1971)
Romein, 1979.
Pontosphaera panarium (Deflandre in Deflandre & Fert,
1954) Aubry, 1986
Pl.14, figs 14-15. Like P. versa but plate dark in XPL.
Occurrence: NP23; TDP Sites 1, 6.
Pontosphaera ocellata (Bramlette & Sullivan, 1961)
Perch-Nielsen, 1984
Pl.14, figs 16-18. Simple, unadorned plate with two closely spaced, longitudinally-arranged holes; rim/margin usually distinct from plate in XPL, but not as high as in, e.g.,
P. versa. Difficult to systematically differentiate fromother species, e.g. Pontosphaera exilis. Occurrence:
NP11; TDP Site 3.
Pontosphaera duocava (Bramlette & Sullivan, 1961)
Romein, 1979
Pl.14, figs 19-20. Simple, unadorned plate with two widely-spaced, longitudinally-arranged holes; rim usually distinct from plate in XPL, and can be relatively high.

32

Bown

Difficult to systematically differentiate from otherspecies. Occurrence: NP11; TDP Site 3.

of small holes near centre of plate. Occurrence: NP15b;
TDP Site 2. Rare.

Pontosphaera exilis (Bramlette & Sullivan, 1961)
Romein, 1979
Pl.14, figs 21-30. Simple, unadorned plate with two large
holes that define a transverse bar; rim narrow and not distinct in XPL. Hole size, and thus bar-width, vary greatly.
Bar typically transverse but may be slightly oblique. This
species concept is similar to that of Pontosphaera rectipons Haq, 1968 but the holotype of the latter is poor andprobably not a pontosphaerid. Occurrence: NP9b/10-17;
TDP Sites 2, 3, 4, 7A, 7B, 8.
Pontosphaera obliquipons (Deflandre in Deflandre &Fert, 1954) Romein, 1979
Pl.14, figs 31-35. Simple, unadorned plate with large,
central hole spanned by oblique bar that is crystallographically disjunct. Bar birefringent at 0° (i.e. when the coccolith is orientated parallel to the polarisers) and dark at
10°. Occurrence: NP14b/15a-15c; TDP Sites 1, 2, 6.

Pontosphaera clinosulcata sp. nov.
Pl.15, figs 21-25. Derivation of name: From sulcus,
meaning furrow, and clinatus, meaning inclined, referringto the inclined furrows and pores that characterise thiscoccolith. Diagnosis: Medium to large, elliptical coccolith with a plate that is scalloped towards its outer edge.
Scalloping defined by narrow, inclined ridges that run
inwards towards the centre. There are inclined furrows
between the ridges and inclined elongate pores; there may
be two central, longitudinal slits. Rim narrow and difficult
to distinguish in XPL. Differentiation: Similar to P.
pectinata but characterised by distinctly inclined poresand furrows. Dimensions: L = 7.7-9.8µm. Holotype:
Pl.15, fig.22 (fig.21 same specimen). Paratype: Pl.15,
fig.24. Type locality: TDP Site 2, Kilwa Masoko,
Tanzania. Type level: Middle Eocene, Sample TDP2-241, 27cm (Subzone NP15b). Occurrence: NP15b; TDP
Site 2.

Pontosphaera rimosa (Bramlette & Sullivan, 1961) Roth& Thierstein, 1972
Pl.15, figs 1-5. Simple, unadorned plate with large, central hole; rim narrow and not distinct from plate in XPL.
Occurrence: Intra-NP9b; TDP Site 10.

Pontosphaera punctosa (Bramlette & Sullivan, 1961)
Perch-Nielsen, 1984
Pl.15, figs 26-30. Plate with marginal furrows and small
pores, with larger pores towards the centre. Occurrence:
NP10; TDP Site 7A.

Pontosphaera multipora (Kamptner, 1948 ex Deflandre,
1954) Roth, 1970
Pl.15, figs 6-12. Simple, unadorned plate with up to three
concentric cycles of small perforations; rim narrow andnot distinct from plate in XPL. Occurrence: NP14b/1523; TDP Sites 1, 2, 4, 6.

Pontosphaera perforomarginata sp. nov.
Pl.15, figs 31-33. Derivation of name: From marginatus,
meaning margin, and perforo, meaning pierced, referringto the central-area pores that characterise this coccolith.
Diagnosis: Large, elliptical coccolith with plate piercedby small pores and two central, longitudinal holes thatdefine a conjunct bar. Plate thickens towards edge but rim
difficult to distinguish in XPL. Differentiation: Similar
to P. multipora but with two longitudinal holes.
Dimensions: L = 7.9-9.0µm. Holotype: Pl.15, fig.32(fig.33 same specimen). Paratype: Pl.15, fig.31. Type
locality: TDP Site 3, Mpara Hill, Tanzania. Type level:
Lower Eocene, Sample TDP3-11-1, 56cm (Zone NP11).
Occurrence: NP11; TDP Site 3.

Pontosphaera distincta (Bramlette & Sullivan, 1961)
Roth & Thierstein, 1972
Pl.15, figs 13-15. Large, thick coccolith (orange birefringence in XPL) with broad, thickened rim/margin and relatively thick, narrow, perforate central plate. Occurrence:
NP15b-c; TDP Site 2.
Pontosphaera pectinata group
Pontosphaerids with rims and plates that are adorned withdepressions, furrows and slits.
Pontosphaera pectinata (Bramlette & Sullivan, 1961)
Sherwood, 1974
Pl.15, figs 16-18. Plate scalloped towards outer edge andpierced by two longitudinal slits or small holes. The scalloping is defined by narrow, radial ridges and furrows thatrun inwards towards the centre. Occurrence: NP11-17;
TDP Sites 2, 3, 4, 6.
Pontosphaera cf. P. pectinata (Bramlette & Sullivan,
1961) Sherwood, 1974
Pl.15, figs 19-20. Like P. pectinata but with single cycle

Pontosphaera pulchra (Deflandre in Deflandre & Fert,
1954) Romein, 1979
Pl.15, figs 34-35; Pl.16, figs 1-3. Like P. pectinata but thetwo central holes larger, defining transverse bar.
Occurrence: NP11-14b/15a; TDP Sites 2, 3.
Pontosphaera pulcheroides (Sullivan, 1964) Romein,
1979
Pl.16, figs 4-5. The central-area plate has a row of small
pores towards its outer edge and a large central holespanned by an oblique, transverse bar. Occurrence:
NP14b/15a; TDP Site 2. Rare.

Palaeogene calcareous nannofossils...Tanzania

Pontosphaera formosa (Bukry & Bramlette, 1968)
Romein, 1979
Pl.16, figs 6-16. Large (9-17µm), with high, flaring rimthat displays discernible elements in LM. Plate thin andindistinct in XPL. Occurrence: NP14b/15a-17; TDP Sites
2, 4, 6.
Pontosphaera fimbriata (Bramlette & Sullivan, 1961)
Romein, 1979
Pl.16, figs 17-18. Like P. formosa but plate has two large
holes that define a transverse bar. Occurrence: NP14b15a; TDP Site 2.
Genus Scyphosphaera Lohmann, 1902
For reviews see Aubry (1990) and Siesser (1998).
Scyphosphaera apsteinii Lohmann, 1902
Pl.16, figs 19-21; Pl.17, fig.1. Large (up to 24µm), elevated murolith (i.e. cup-, barrel-, or vase-shaped; lopadolithsof some authors) with variable morphology but typicallybroad, with curved, gently flaring walls that may narrow
distally. Occurrence: NP14b/15b; TDP Site 2. Rare.
NP12-living (Siesser, 1998).
Scyphosphaera columella Stradner, 1969
Pl.16, fig.22; Pl.17, figs 2-5. Tall (up to 26µm), narrowmurolith with near-straight walls that are parallel, or veryslightly flaring to a maximum width at the distal end.
Occurrence: NP15bc; TDP Site 2. Rare. NP12-16(Siesser, 1998).
Scyphosphaera cylindrica Kamptner, 1955
Pl.16, fig.23; Pl.17, figs 6-7. Tall (up to 26µm), relatively
broad murolith with straight, parallel-sided walls.
Occurrence: NP15b; TDP Site 2. Rare. NP12-NN21a(Siesser, 1998).
Scyphosphaera expansa Bukry & Percival, 1971
Pl.16, figs 24-25; Pl.17, figs 11-13. Tall (up to 31µm), relatively broad murolith with flaring walls. Occurrence:
NP15b-c; TDP Site 2. Rare. NP12-NN21a (Siesser, 1998).
Scyphosphaera tercisensis Lezaud, 1969
Pl.16, fig.26
Family ZYGODISCACEAE Hay & Mohler, 1967
Lophodolithus acutus Bukry & Percival, 1971
Pl.18, figs 6-7
Lophodolithus nascens Bramlette & Sullivan, 1961
Pl.18, figs 1-5
Lophodolithus mochlophorus Deflandre in Deflandre &Fert, 1954
Pl.18, figs 11-12
Lophodolithus rotundus Bukry & Percival, 1971
Pl.18, figs 8-10, 13-14

33

Zygodiscus plectopons Bramlette & Sullivan, 1961
Pl.18, figs 15-24. Murolith with wide central-areaspanned by parallel side-bar. Some specimens (Pl.18, figs
20-22) show more complex bar construction with crystallographically-distinct units. Occurrence: NP9b-11; TDP
Sites 3, 7A, 7B, 10. Synonyms: Zygodiscus bramlettei
Perch-Nielsen, 1981; Zygodiscus herlynii Sullivan, 1964.
Zygodiscus sheldoniae sp. nov.
Pl.18, figs 25-34. Derivation of name: After Emma
Sheldon (GEUS, Denmark), nannopalaeontologist.
Diagnosis: Medium- to large-sized murolith, with broad
plate enclosing small disjunct bar. Remarks: Like
Zygodiscus clausus, this species may represent intermediate morphology between the genera Pontosphaera and
Zygodiscus. Differentiation: Like pontosphaerids butwith a disjunct bar. Similar to Z. clausus but with broader
plate and smaller bar. Dimensions: L = 6.6-9.5µm.
Holotype: Pl.18, fig.27 (figs 28, 29 same specimen).
Paratype: Pl.18, fig.32 (figs 33, 34 same specimen).
Type locality: TDP Site 10, Singino Hill, Tanzania. Typelevel: Upper Paleocene, Sample TDP10-14-1, 50cm
(Subzone NP9b). Occurrence: NP9b; TDP Site 10.
Zygodiscus clausus Romein, 1979
Pl.19, figs 1-5. Medium-sized, elliptical murolith comprising an unadorned plate with central hole spanned andfilled by a disjunct bar; rim narrow and cannot be differentiated in XPL. The precise crystallographic orientationof the bar appears to vary. This morphology may represent
a transitional form between the genera Zygodiscus andPontosphaera. Occurrence: NP9b; TDP Site 10.
Neochiastozygus concinnus (Martini, 1961) PerchNielsen, 1971
Pl.19, figs 6-10. Diagonal cross with bars that do not flareat their ends. Cross-bars make an angle of ~40°.
Occurrence: NP9b/10; TDP Site 7B.
Neochiastozygus rosenkrantzii (Perch-Nielsen, 1971)
Varol, 1989
Pl.19, figs 11-20. Broad, diagonal cross-bars that flare attheir ends. General trend towards larger coccoliths
through its range. Cross-bars make an angle of ~40°.
Occurrence: NP9b-11; TDP Sites 3, 7A, 7B, 8, 10.
Neochiastozygus substrictus sp. nov.
Pl.19, figs 21-25. Derivation of name: From substrictus,
meaning narrow, referring to the outline that characterises
this coccolith. Diagnosis: Medium-sized, narrowly elliptical murolith with slightly asymmetrical, diagonal cross.
Cross-bars make an angle of 30-40°. Dimensions: L =6.4-8.0µm; W = 3.3-3.9µm. Holotype: Pl.19, fig.24(fig.23 same specimen). Paratype: Pl.19, fig.22 (fig.21
same specimen). Type locality: TDP Site 10, Singino
Hill, Tanzania. Type level: Upper Paleocene, Sample
TDP10-40-3, 68cm (Subzone NP9b). Occurrence:

34

Bown

NP9b-10; TDP Sites 7B, 10.
Neochiastozygus junctus (Bramlette & Sullivan, 1961)
Perch-Nielsen, 1971
Pl.19, figs 26-30. Large coccoliths with diagonal crossbars that form an angle of ~20°. Occurrence: NP9b/1011; TDP Sites 3, 7A, 7B, 8.
Neochiastozygus imbriei Haq & Lohmann, 1975
Pl.19, figs 31-35. Narrow-rimmed Neochiastozygus withnarrow, typically asymmetric, curving cross-bars thatcross at an obtuse angle. Previously recorded from theLower Paleocene only (Perch-Nielsen, 1985).
Occurrence: NP9b-11; TDP Sites 3, 7A, 8, 7B, 10.
Neochiastozygus distentus (Bramlette & Sullivan, 1961)
Perch-Nielsen, 1971
Pl.20, figs 1-5. Neochiastozygus with narrow central-areafilled with diagonal cross-bars that are embedded into therim. Occurrence: NP9b-10; TDP Sites 7A, 7B.
Synonym: Neocrepidolithus bukryi Perch-Nielsen, 1981.
Neochiastozygus macilentus sp. nov.
Pl.20, figs 6-10. Derivation of name: From macilentus,
meaning thin or skinny, and referring to the narrow rim
and bars of these coccoliths. Diagnosis: Medium to large
Neochiastozygus coccoliths with narrow rim and wide
central-area spanned by narrow cross-bars that make anangle of ~30°. Dimensions: L = 8.4-9.1µm. Holotype:
Pl.20, fig.8 (fig.7 same specimen). Paratype: Pl.20, fig.9(fig.10 same specimen). Type locality: TDP Site 7B,
Kwamatola, Tanzania. Type level: Lower Eocene,
Sample TDP7B-48-1, 30cm (Zone NP10). Occurrence:
NP9b/10-10; TDP Site 7B.
Neococcolithes protenus (Bramlette & Sullivan, 1961)
Black, 1967
Pl.20, figs 11-15
Order SYRACOSPHAERALES Hay, 1977 emend.
Young et al., 2003
Family CALCIOSOLENIACEAE Kamptner, 1927
Calciosolenia fossilis (Deflandre in Deflandre & Fert,
1954) Bown in Kennedy et al., 2000
Pl.20, figs 16-17
Calciosolenia aperta (Hay & Mohler, 1967) comb. nov.
Pl.20, figs 18-20. Basionym: Scapholithus apertus Hay &Mohler, 1967, p.1534, pl.201, fig.12; Journal of
Paleontology, 41: 1505-1541. Remarks: The genus
Scapholithus is a junior synonym of the extant genus
Calciosolenia (see discussions in Bown in Kennedy et al.,
2000; Young et al., 2003). Synonym: Scapholithus
rhombiformis Hay & Mohler, 1967.

Family SYRACOSPHAERACEAE Lemmermann,
1908
Syracosphaera? tanzanensis sp. nov.
Pl.20, figs 21-25. Derivation of name: From Tanzania,
the type area of this material. Diagnosis: Medium-sized
muroliths with narrow, bicyclic rim (bright inner-cycle,
dark outer-cycle) and wide central-area. Central-areastructure not clear in LM but may be a thin plate.
Differentiation: Similar to larger Neogene and extant
Syracosphaera coccoliths, hence the tentative genericdesignation, but the bright cycle is more dominant in the
XPL image. Dimensions: L = 5.1-5.4µm. Holotype:
Pl.20, fig.23 (figs 24, 25 same specimen). Paratype:
Pl.20, fig.21 (fig.22 same specimen). Type locality: TDP
Site 1, Kilwa Masoko, Tanzania. Type level: Lower
Oligocene, Sample TDP1-20-2, 24cm (Zone NP23).
Occurrence: NP23; TDP Site 1.
Family RHABDOSPHAERACEAE Haeckel, 1894
Genus Blackites Hay & Towe, 1962
Most of the Tanzanian Palaeogene rhabdolith coccoliths
display comparable rim structure in LM. Two distinct
units are visible: an inner cycle that is widest, thickest,
and brightest in side and plan views, and an outer cyclethat is darker and smaller. The outer cycle can lie distallyover the inner cycle, or side by side, but always protrudes
further laterally, forming the outer edge of the coccolith.
All rhabdoliths showing this structure have been includedin Blackites. There are a number of informal groupings
used below but I submit that electron microscope study
may reveal morphological features that allow further systematic subdivision of the group. See also Shafik (1989),
Kleijne (1992) and Aubry (1999) for taxonomic reviewsof the family.
Blackites gladius group
Moderately tall, and narrow to wide, spines with distinct
rim structure, only seen in this group (B. creber, B. gladius, B. rotundus), in which the outer cycle lies distallyover the inner cycle (see above).
Blackites creber (Deflandre in Deflandre & Fert, 1954)
Sherwood, 1974
Pl.21, figs 1-9. Rhabdoliths with tall, narrow, hollow,
styliform spines, near-parallel for much of their length,
but that may broaden slightly in the upper half. Upper
quarter of spines display distinctive striated pattern.
Coccolith relatively broad, spine usually less than half its
width, and may show a basal collar. Differentiation:
Similar to Blackites gladius but with a narrower spine thatis near-parallel for much of its length; the two species
probably intergrade. Dimensions: H = 13.1-18.4µm; CW= 4.1-5.8µm; SW = 1.0-2.3µm. Occurrence: NP14b/15ac; TDP Sites 2, 4, 6.

Palaeogene calcareous nannofossils...Tanzania

Blackites gladius (Locker, 1967) Varol, 1989
Pl.21, figs 10-14. Rhabdoliths with hollow, flask-likespines that are narrow at their base, widen to a maximum
around three-quarters of the way up, and taper to a point;
upper half of spines display distinctive striated pattern.
Coccoliths broad, and spine usually around half the width,with prominent basal collar. Differentiation: Similar to B.
creber but with a broader, more inflated, spine; the two
species probably intergrade. Blackites rotundus has similar morphology but a more globose spine; the two species
probably intergrade. The rim structure is distinctly different to other coccoliths with similar spine morphologies,
such as Blackites bullatus. Dimensions: H = 5.7-10.8µm;
CW = 4.7-5.6µm; SW = 2.0-2.8µm. Occurrence:
NP14b/15a-17; TDP Sites 2, 4, 6.
Blackites rotundus sp. nov.
Pl.21, figs 15-19. Derivation of name: From rotundus,
meaning rounded, referring to the globose spine morphology. Diagnosis: Rhabdoliths with hollow, flask-likespines that are narrow at their base, and wide and rounded distally; inflated part of spine displays distinctive striated pattern. Coccolith broad, and outer cycle lies distallyover inner cycle and forms outer edge of coccolith. Spine
greater than half width of coccolith, and usually has aprominent basal collar. Differentiation: Similar to B. gladius but with a broader, rounder, more-inflated spine.
Dimensions: H = 7.1-8.5µm; CW = 4.3-5.5µm; SW =3.1-3.7µm. Holotype: Pl.21, fig.17 (figs 15, 16 same
specimen). Paratype: Pl.21, fig.19. Type locality: TDP
Site 2, near Kilwa, Tanzania. Type level: Middle Eocene,
Sample TDP2-2-1, 15cm (Subzone NP15c). Occurrence:
NP15b-c; TDP Site 2.
Blackites morionum group
Short to moderately tall and wide spines, and typicalBlackites rim-structure in which the two cycles lie side byside, the outer cycle being smaller.
Blackites morionum (Deflandre in Deflandre & Fert,
1954) Varol, 1989
Pl.21, figs 20-24. Rhabdolith with relatively low, wide,
hollow, sacculiform spine; there may be a small, terminal
papilla. Coccolith relatively broad, and typically theheight and width are similar. The spine broadens slightly
before tapering to a point and is always slightly narrower
than the coccolith rim. Dimensions: H = 3.6-4.6µm; CW= 3.6-5.6µm; SW = 2.5-4.4µm. Occurrence: NP9b-23;
TDP Sites 1, 2, 3, 4, 6, 7A, 7B 8, 10.
Blackites cf. B. morionum (Deflandre in Deflandre &Fert, 1954) Varol, 1989
Pl.21, figs 25-29. Like B. morionum but spine taller andterminates rather abruptly and bluntly. Occurrence:
NP11-14b/15a; TDP Sites 2, 3.
Blackites gamai sp. nov.
Pl.21, figs 30-34; Pl.22, figs 1-5. Derivation of name:35

After Rui da Gama, nannopalaeontologist (Network
Stratigraphic, UK). Diagnosis: Rhabdolith with broad,hollow, bullet-shaped spine that initially broadens slightly before tapering gently to a point. Typically, height ofspine greater than coccolith width. Dimensions: H = 6.16.5µm; CW = 4.3-4.4µm. Holotype: Pl.21, fig.34 (figs
30-33 same specimen). Paratype: Pl.22, fig.1 (figs 2, 3
same specimen). Type locality: TDP Site 3, Mpara Hill,
Tanzania. Type level: Lower Eocene, Sample TDP3-5-1,
13cm (Zone NP11). Occurrence: NP11; TDP Site 3.
Blackites bullatus sp. nov.
Pl.22, figs 6-10. Derivation of name: From bullatus,
meaning inflated, referring to the spine shape. Diagnosis:
Rhabdolith with hollow, bulb-shaped spine (maximum
width similar to that of the coccolith); rim relatively broadand outer cycle does not lie distally over inner cycle.
Differentiation: Similar to Blackites globosus but with anarrower spine, and B. rotundus but has a broader, morerounded spine and an outer rim-cycle that does not lie distally above the inner cycle. Dimensions: H = 9.9-11.0µm;
CW = 3.9-4.6µm; SW = 2.2-2.9µm. Holotype: Pl.22,
fig.6. Paratype: Pl.22, fig.8. Type locality: TDP Site 2,near Kilwa, Tanzania. Type level: Middle Eocene,
Sample TDP2-35-2, 49cm (Subzones NP14b/15a).
Occurrence: NP14b/15a; TDP Site 2 (several questionable specimens were also recorded from NP15b andNP15c of the same section).
Blackites globosus sp. nov.
Pl.22, figs 11-20. Derivation of name: From globosus,
meaning rounded or spherical, referring to the shape ofthe spine. Diagnosis: Rhabdolith with hollow spine that
rapidly expands into a sphere (maximum width almost
twice that of the coccolith). Spine has a short, narrow collar, a pinched distal termination, and shows a distinctive
cross-hatched pattern in its upper part. Rim relatively
broad and outer cycle does not lie distally over innercycle. Differentiation: Similar to B. bullatus but with aspine that is near spherical. Dimensions: H = 10.010.4µm; CW = 3.8-4.0µm; SW = 1.42-1.49µm.
Holotype: Pl.22, fig.11 (figs 12, 13 same specimen).
Paratype: Pl.22, fig.14 (fig.15 same specimen). Type
locality: TDP Site 6, near Kilwa, Tanzania. Type level:
Middle Eocene, Sample TDP6-8-1, 63.5cm (Subzone
NP15b). Occurrence: NP15b; TDP Sites 2, 6.
Blackites fustis sp. nov.
Pl.22, figs 21-25. Derivation of name: From fustis,
meaning club, referring to the spine shape. Diagnosis:
Rhabdolith with relatively wide, hollow, flask-like spinethat is initially near-parallel-sided, expands distally, andthen terminates sharply in a domed top, often with a small
papilla. The spine reaches a width similar to that of thecoccolith. Rim relatively broad and outer cycle does notlie distally over inner cycle. Differentiation: Resembles
B. rotundus, B. gladius and B. bullatus but has distinct

36

Bown

spine morphology, particularly the rapid termination toform a domed spine-top. Dimensions: H = 6.2-6.9µm;
CW = 3.7-4.5µm; SW = 3.7-4.6µm. Holotype: Pl.22,
fig.21 (fig.22 same specimen). Paratype: Pl.22, fig.24.
Type locality: TDP Site 2, near Kilwa, Tanzania. Typelevel: Middle Eocene, Sample TDP2-2-1, 15cm (Subzone
NP15c). Occurrence: NP15b-15c; TDP Sites 2, 6.
Blackites pseudomorionum (Locker, 1967) Aubry, 1999
Pl.22, figs 26-30. Rhabdoliths with relatively tall, broad,hollow spine that widens to a maximum, and then tapers
sharply to a point, forming a distinctive angular inflection
point. The inflection point appears to be at the junction of
two structural units that are distinct in XPL. Typically,spine much taller than (x2), but approximately same
width as, coccolith. Dimensions: H = 5.8-9.0µm; CW =3.8-3.9µm; SW = 3.7-4.9µm, but smaller forms also occur(3.7µm x 1.7µm x 2.2µm). Occurrence: NP14b/15a-c;
TDP Site 2 (possibly Oligocene, TDP Site 1). Rare.
Blackites deflandrei (Perch-Nielsen, 1968) comb. nov.
Pl.22, figs 31-35. Basionym: Naninfula deflandrei PerchNielsen, 1968, p.2299, pl.1, fig.3; C. R. Acad. Sci., Paris,
267: 2298-2300. Remarks: Rhabdolith with relatively
low, wide, hollow, sacculiform spine, constructed from atleast two distinct structural units when viewed in XPL;
there may be a small, terminal papilla. Typically, height
and width similar but height can be greater. Spine broadens slightly to a maximum in the lower cycle, before
tapering to a point; spine always slightly narrower thancoccolith. The holotype is an electron micrograph but
appears to represent the same morphology as thoserecorded here (see also Aubry, 1999). The rim-structureappears identical to other Blackites rhabdoliths of thisage, and the species is therefore placed within this genus.
Differentiation: Similar to B. morionum but has multicycle spine-construction when viewed in XPL.
Dimensions: H = 3.3-6.1µm; CW = 4.2-4.3µm; SW =2.1-4.1µm. Occurrence: NP14b/15a-c; TDP Site 2.
Blackites bipartitus sp. nov.
Pl.23, figs 1-5. Derivation of name: From bipartitus,
meaning divided into two, referring to the two-part construction of the spine. Diagnosis: Rhabdolith with flasklike spine, constructed from two distinct structural units
when viewed in XPL. The short lower-spine unit broadens
away from the coccolith and the longer upper-spine cycle
tapers to a point. Rim dominated by inner of the twocycles; outer cycle does not lie distally over inner cycle.
Typically, height is around twice width, and maximum
spine width is similar to that of coccolith.
Differentiation: The two-part spine structure is similar tothat seen in B. deflandrei and B. pseudomorionum, but thelower-spine unit is smaller and the upper-spine cycle
longer. Dimensions: H = 5.1-6.2µm; CW = 2.7-3.0µm;
SW = 2.7-3.0µm. Holotype: Pl.23, fig.1 (figs 2, 3 same
specimen). Paratype: Pl.23, fig.4 (fig.5 same specimen).

Type locality: TDP Site 2, near Kilwa, Tanzania. Typelevel: Middle Eocene, Sample TDP2-28-1, 50cm
(Subzone NP15b). Occurrence: NP14b/15a; TDP Site 2.
Blackites turritus sp. nov.
Pl.23, figs 6-10. Derivation of name: From turritus,
meaning having turrets, referring to the turret-like spine
morphology. Diagnosis: Rhabdolith with tall spine, constructed from at least two or three distinct structural/crystallographic units when viewed in XPL; there may be asmall, terminal papilla. Typically, spine taller than widthof coccolith, and near-parallel-sided, or slightly tapering,
before terminating quite sharply; spine usually about half
width of coccolith. Rim relatively broad and outer cycle
does not lie distally over inner cycle. Dimensions: H =3.9-5.8µm; CW = 3.6-4.6µm; SW = 2.2-2.7µm.
Holotype: Pl.23, fig.6 (figs 7, 8 same specimen).
Paratype: Pl.23, fig.10. Type locality: TDP Site 7B, near
Kwamatola, Tanzania. Type level: Lower Eocene,
Sample TDP7B-33-1, 20cm (Zone NP10). Occurrence:
NP9b/10-10; TDP Sites 7A, 7B.
Blackites clavus sp. nov.
Pl.23, figs 11-15. Derivation of name: From clavus,
meaning nail, referring to the general shape of the coccolith and spine. Diagnosis: Rhabdolith coccoliths with shortspine that tapers rapidly to a point. Typically, spine similar in height to width of coccolith. Rim relatively broad;outer cycle small and does not lie distally over innercycle. In overall shape, coccolith and spine resemble ashort nail or pin. Differentiation: The spine tapers fromthe base and thus differs from most other morphologies in
the B. morionum group. Dimensions: H = 5.2-5.5µm; CW= 3.6-3.9µm; SW = 2.1-2.2µm. Holotype: Pl.23, fig.11.
Paratype: Pl.23, fig.13. Type locality: TDP Site 7A, near
Kwamatola, Tanzania. Type level: Lower Eocene,
Sample TDP7A-57-1, 55cm (Zone NP10). Occurrence:
NP10; TDP Sites 7A, 7B, 8.
Blackites atanii (Varol, 1989) comb. nov.
Pl.23, figs 16-20. Basionym: Cruxia atanii Varol, 1989,
p.292, pl.4, figs 25-27; Rev. Española de Micropaleont.,
XXI: 273-320. Remarks: Small rhabdolith with relatively low, hollow, sacculiform spine that broadens rapidly
from a narrow base, and then tapers to form a low, pointed dome. Typically, height and width are similar; spine
similar in width to, or slightly wider than, coccolith. All
specimens have identical LM rim-structure to other
Palaeogene rhabdoliths and the species is therefore
included in Blackites. Differentiation: Resembles B.
morionum but the spine broadens from a narrow neck at
the spine-base. Dimensions: H = 2.5-3.9µm; CW = 2.23.2µm; SW = 2.7-3.1µm. Occurrence: NP11-NP15b;
TDP Sites 2, 3.
Cruxia mericii Varol, 1989
Pl.23, figs 21-25. Small rhabdoliths with relatively low,hollow, sacculiform spines. Spine broadens from base andPalaeogene calcareous nannofossils...Tanzania

is capped by curving upper surface that appears to be constructed from two parts (XPL); spine usually slightly
wider than coccolith. Coccolith rim appears to be narrow,and only one cycle has been observed. Dimensions: H =2.3-3.0µm; CW = 2.7-2.8µm; SW = 2.8-3.2µm.
Occurrence: NP15b; TDP Sites 2, 6. NP12 (Varol, 1989).
Blackites perlongus group
Tall, narrow spines and typical Blackites rim.
Blackites herculesii (Stradner, 1969) Bybell & Self-Trail,
1997
Pl.23, figs 26-30. Rhabdolith with broad, claviform spine,
and with typical width only slightly less than that of coccolith. Spine displays distinctive cross-hatched patternand outer surface may be serrated. Outer cycle of coccolith rim significantly smaller than inner. Differentiation:
Similar to Blackites perlongus but with a broader spine.
Dimensions: H = 10.1-12.0µm; CW = 3.8-4.0µm; SW =2.8-3.9µm. Occurrence: NP9b/10-11; TDP Sites 3, 7A,
7B, 8.
Blackites perlongus (Deflandre, 1952) Shafik, 1981
Pl.24, figs 1-10. Rhabdolith with tall, narrow, claviform
spine that is never as broad as coccolith rim. Rim usuallyrelatively narrow and outer cycle significantly smaller
than inner. Some specimens have a collar at the base of
the spine. Differentiation: Like B. herculesii but with anarrower, often taller, spine; the two species probablyintergrade. Dimensions: H = 7.8-30.3µm; CW = 1.73.4µm; SW = 1.3-1.7µm. Occurrence: NP9b-17; TDP
Sites 1 2, 3, 4, 6, 8 (NP23? at TDP Site 1).
Blackites inflatus (Bramlette & Sullivan, 1961) Kapellos& Schaub, 1973
Pl.24, figs 11-15. Rhabdolith with tall, narrow, hollow,
flask-like spine that broadens to a maximum width, thentapers gradually in upper portion; outer surface serrated.
Width of spine variable and, typically, same as coccolith,
but considerably taller (x4-7). Rim distinctly convex andrelatively broad. Dimensions: H = 16.9-21.7µm; CW =3.0-5.0µm; SW = 3.0-5.6µm. Occurrence: NP14b/15a;
TDP Site 2.
Blackites spinosus (Deflandre & Fert, 1954) Hay &Towe, 1962
Pl.24, figs 16-25. Rhabdolith with tall, narrow, styliform
spine that tapers gradually to a point; outer surface
smooth. Width of spine around half that of coccolith but
considerably taller (x4-6). Rim relatively broad and distinctly convex. Differentiation: Blackites scabrosus(Deflandre in Deflandre & Fert, 1954) Roth, 1970 andBlackites tenuis (Bramlette & Sullivan, 1961) Sherwood,
1974 have similar morphologies but could not be reliably
differentiated from B. spinosus in this study. Dimensions:
H = 16.8-25.2µm; CW = 2.8-4.5µm; SW =1.7-2.7µm.
Occurrence: NP14b/15a-23; TDP Sites 1, 2, 6. Rare and37

sporadic.
Other Blackites coccoliths
Blackites piriformis (Pavsic in Khan et al., 1975 ) Aubry,
1999
Pl.25, figs 1-5. Rhabdoliths with wide, hollow, flask-likespine that broadens rapidly to a maximum width, thentapers to a narrow upper portion; inflated part of spine displays distinctive cross-hatched pattern; outer surface serrated. Spine much taller (x3) and wider than coccolith.
Dimensions: H = 11.0-12.7µm; CW = 3.6-3.8µm; SW =5.0-6.6µm. Occurrence: NP14b/15a-23; TDP Sites 1 2.
Rare and sporadic.
Blackites virgatus sp. nov.
Pl.25, figs 6-15. Derivation of name: From virgatus,
meaning striped, referring to the distinct appearance ofthe spine. Diagnosis: Large rhabdoliths with tall, hollow
spine that is widest at its base, tapers to a point, and is distinctively coarsely striated in XPL. Rim broad and outercycle does not lie distally over inner cycle. Screw-like inoverall appearance. Differentiation: Blackites spines areoften striated in distal parts but never as strongly or ascompletely as in this species. Dimensions: H = 15.617.2µm; CW = 5.4-5.5µm; SW = 2.3-2.7µm. Holotype:
Pl.25, fig.11 (figs 12, 13 same specimen). Paratype:
Pl.25, fig.14. Type locality: TDP Site 2, near Kilwa,
Tanzania. Type level: Middle Eocene, Sample TDP2-2-1,
15cm (Subzone NP15c). Occurrence: NP15b-c; Site
TDP2.
Blackites dupuisii (Steurbaut, 1990) comb. nov.
Pl.25, figs 16-19. Basionym: Naninfula dupuisii
Steurbaut, 1990, p.267, pl.4, fig.3; Bull. de la Soc. Belgede Géol., 97: 251-285. Remarks: Rhabdoliths with a tall,tapering, hollow spine that is broad at its base but tapering and narrow in its upper half. Two or three spine-cycles
are seen low on the spine, along with striated ornamentation. The spine is usually around two to three times taller
the coccolith. Dimensions: H = 5.1-9.8µm; CW = 3.04.4µm; SW = 2.4-3.3µm. Occurrence: NP9b-NP15b;
TDP Sites 2, 6, 7A, 7B, 10. Upper NP11 (Steurbaut,1990).
Blackites cf. B. dupuisii (Steurbaut, 1990) comb. nov.
Pl.25, fig.20. Like B. dupuisii but the spine tapers uniformly from its wide base. Dimensions: H = 7.4µm; CW= 4.6µm; SW = 3.5µm. Occurrence: NP15b; TDP Site 2.
Blackites vitreus (Deflandre in Deflandre & Fert, 1954)
Shafik, 1981
Pl.25, figs 21-25. Rhabdoliths with very narrow, styliform
spine that typically has a prominent basal collar.
Coccolith broad and thin, and dominated by inner cycle,
with outer cycle forming only the outermost edge.
Differentiation: Spine much thinner than most other

38

Bown

Palaeogene rhabdoliths. Dimensions: H = 2.5-13.5µm;
CW = 2.4-5.2µm. Occurrence: NP11-23; TDP Sites 1, 2,
3, 4.

Pseudotriquetrorhabdulus inversus (Bukry & Bramlette,1969) Wise in Wise & Constans, 1976
Pl.26, figs 29-30

Blackites kilwaensis sp. nov.
Pl.25, figs 26-30. Derivation of name: From the villageof Kilwa, near the type locality of Site TDP2. Diagnosis:
Rhabdoliths with tall, narrow, salpingiform spine that terminates in a sharply tapering spine top; rim small andonly one cycle is visible in LM. Differentiation: Similar
to Rhabdolithus poculi Bóna & Kernerné-Sümegi, 1966,
described from the Hungarian Miocene, but generally
taller and narrower in overall form. Dimensions: H = 6.310.6µm; CW = 0.7-1.1µm; SW = 1.5-3.4µm. Holotype:
Pl.25, fig.26 (figs 27, 28 same specimen). Paratype:
Pl.25, fig.30. Type locality: TDP Site 2, near Kilwa,
Tanzania. Type level: Middle Eocene, Sample TDP2-212, 70cm (Subzone NP15b). Occurrence: NP14b/15a-15c;
TDP Sites 2, 6.

6.3 Holococcoliths

Blackites? stilus sp. nov.
Pl.26, figs 1-10. Derivation of name: From stilus, meaning stake, referring to the distinct shape of this nannolith.
Diagnosis: A rhabdolith-like nannofossil, comprisingtapering, spine-like structure with narrow to broad central
canal. No basal coccolith yet observed at wider end,
although a distinct widening occurs. Dimensions: H =13.3-22.3µm; W = 2.0-4.2µm. Holotype: Pl.26, fig.3(fig.4 same specimen). Paratypes: Pl.26, fig.9; Pl.26,
fig.5. Type locality: TDP Site 2, near Kilwa, Tanzania.
Type level: Middle Eocene, Sample TDP2-23-1, 1cm(Subzone NP15b). Occurrence: NP14b/15a-15c; TDP
Sites 2, 6.
Blackites bases
Pl.26, figs 16-25. Bases of Blackites rhabdolith coccoliths
were found throughout the studied sections but were notlogged as distinct species, and have not been linked to theside views described above. A number of specimens are
figured but the taxonomy is informal. All are circular andcharacterised by two visible cycles, an outer dark cycle(in XPL) (V unit) and an inner bright cycle (R unit),
crossed by curving, but approximately N-S-trending,extinction lines. Dimensions: W = 4.0-6.6µm.
‘Anacanthoica mitra’ Varol, 1989
Pl.26, figs 26-28; Pl.46, figs 16-20. Small, nail-like, twodimensional objects constructed from single calcite crystals, and almost always observed in clusters. Althoughsuperficially resembling rhabdoliths, they appear instead
to be fragments of calcisphere tests of the genus
Scrippsiella (see Janofske, 2000). Dimensions: H = 2.15.0µm; W = 2.1-3.7µm. Occurrence: NP9b/10-15b; TDP
Sites 6, 8, 7A, 7B, 8. Rare and infrequent. Synonym:
Zygrhablithus sagittus Varol, 1989.

Family CALYPTROSPHAERACEAE Boudreaux &Hay, 1967
The higher taxonomy (genera and above) of holococcoliths is problematical at best due both to their rather generalised morphologies and more recent advances demonstrating that many extant holococcolithophores have aseparate heterococcolith life-cycle equivalent. The taxonomy applied here attempts to maintain consistency withprevious taxonomic monographs (e.g. Perch-Nielsen,
1985; Aubry, 1988), applying established generic names
where possible, and for the most part inferring only limited phylogenetic information.
Holodiscolithus macroporus (Deflandre in Deflandre &Fert, 1954) Roth, 1970
Pl.27, figs 1-15. Elliptical, non-birefringent holococcoliths that appear as a dark plate pierced by a variable number of pores (10-16); a distinct rim is sometimes discernible. In side view, a rim and proximal plate can be distinguished from the central, perforate plate. Occurrence:
NP9b/10-23; TDP Sites 1, 2, 3, 4, 7A, 7B, 8.
Holodiscolithus solidus (Deflandre in Deflandre & Fert,
1954) Roth, 1970
Pl.27, figs 16-28. Elliptical holococcoliths comprising a
rim and six central-area bars that are typically weakly- or
non-birefringent. The bars merge centrally to form an
elongate structure that bifurcates at either end, and iscrossed by a transverse bar. In side view, the cavate structure of the holococcolith is evident, along with the rim,
proximal plate, distal cover and bar structures. Some
specimens resemble H. macroporus, having six circularperforations rather than holes delineated by distinct bars;
these are recorded as Holodiscolithus cf. H. solidus (Pl.
27, figs 29-30). Occurrence: NP9b-23; TDP Sites 1, 2, 3,
4, 7A, 7B, 8, 10.
Holodiscolithus serus sp. nov.
Pl.27, figs 31-35. Derivation of name: From sera, meaning bar, referring to the distinct central-area bar of this
holococcolith. Diagnosis: Small, elliptical holococcolithwith narrow rim and small, bright, transverse bar spanning central-area. Dimensions: L = 3.3-3.6µm. Holotype:
Pl.27, fig.31 (figs 32-34 same specimen). Paratype:
Pl.27, fig.35. Type locality: TDP Site 7B, Kwamatola,
Tanzania. Type level: Upper Paleocene, Sample TDP7B50-3, 65cm (Subzone NP9b). Occurrence: NP9b-10;
TDP Sites 7A, 7B, 8, 10.
Holodiscolithus geisenii sp. nov.
Pl.28, figs 1-5. Derivation of name: After Dr. Markus

Palaeogene calcareous nannofossils...Tanzania

Geisen (AWI, Germany), nannopalaeontologist.
Diagnosis: Small, elliptical, rather inconspicuous coccolith with narrow, dark rim and complexly-constructed,
weakly-birefringent, central-area plate. Central platecharacterised by gently curving axial sutures (i.e. blacklines), flanked by small blocks of higher birefringence.
Dimensions: L = 3.2-3.8µm. Holotype: Pl.28, fig.1 (figs
2, 3 same specimen). Paratype: Pl.28, fig.4. Type locality: TDP Site 1, near Kilwa, Tanzania. Type level: Lower
Oligocene, Sample TDP1-10-2, 76cm (Zone NP23).
Occurrence: NP11-23; TDP Sites 1, 2, 3, 6. Rare.
Holodiscolithus minolettii sp. nov.
Pl.28, figs 6-10. Derivation of name: After Dr. Fabrice
Minolettii (Univ. Pierre et Marie Curie, Paris, France),geochemist and nannopalaeontologist. Diagnosis: Small,
elliptical coccolith with narrow, dark rim (visible in PC)
and complexly-constructed, birefringent central-area
plate with bright blocks towards each end. Dimensions: L= 3.9-4.3µm. Holotype: Pl.28, fig. 6 (figs 7, 8 same specimen). Paratype: Pl.28, fig.10 (fig.9 same specimen).
Type locality: TDP Site 4, near Ras Tipuli, Tanzania.
Type level: Middle Eocene, Sample TDP4-5-1, 1cm(Zone NP17). Occurrence: NP15b-17; TDP Sites 2, 4.
Orthozygus aureus (Stradner, 1962) Bramlette &Wilcoxon, 1967
Pl.28, figs 11-22. Elliptical, non-birefringent holococcolith, comprising narrow rim spanned by arched perforate
bridge. Bridge broad and pierced by large, central holeand has a distal covering that is finely perforate.
Distinguishable in both plan and side views. Occurrence:
NP23 (one questionable NP17 specimen); TDP Sites 1, 4.
Orthozygus brytika (Roth, 1970) Aubry, 1988
Pl.28, figs 23-25. Small, narrowly-elliptical, non-birefringent holococcolith, comprising narrow rim spanned bydiagonal cross-bars. Occurrence: NP23; TDP Sites 1, 6.
Rare.
Corannulus horridulus sp. nov.
Pl.28, figs 26-30. Derivation of name: From horridulus,
meaning somewhat rough and unadorned, referring to theoverall morphology of this coccolith. Diagnosis: Smallto medium-sized, elliptical coccolith with broad rim andnarrow vacant central-area. Rim thick and ragged in overall appearance. Dimensions: L = 4.4-6.4µm. Holotype:
Pl.28, fig.26 (figs 27, 28 same specimen). Paratype:
Pl.28, fig.29. Type locality: TDP Site 3, Mpara Hill,
Tanzania. Type level: Lower Eocene, Sample TDP3-4-3,
52cm (Zone NP11). Occurrence: NP10-11; TDP Sites 3,8.
Lanternithus minutus Stradner, 1962
Pl.28, figs 31-35; Pl.29, figs 1-8. Unusual holococcoliththat has typical coccolith morphology in plan view but
nannolith-like appearance in side view. Slightly rectangu-

39

lar in plan view, it has distinct lateral and end rim blocks
and a large, central pore. In side view, it has a box-likeappearance that tapers slightly to one (the distal?) end,
where it is capped by a distal cover. Dimensions: L = 5.25.5µm; H = 3.3-4.2µm. Occurrence: NP14b/15a-23;
TDP Sites 1, 2, 4, 6. FO NP14 (Varol, 1989); LO NP23
(de Kaenel & Villa, 1996).
Lanternithus procerus sp. nov.
Pl.29, figs 11-15. Derivation of name: From procerus,
meaning tall, referring to the tall morphology of this holococcolith. Diagnosis: Medium to large holococcolith seenin side view, comprising basal coccolith formed from twoplates, the upper of which extends distally to form a tallprocess that tapers to a termination, capped by a distal
cover. Spine taller than maximum width of coccolith.
Remarks: More box-like morphologies are named
Lanternithus cf. L. procerus (Pl.29, figs 9-10).
Differentiation: Similar to side views of L. minutus buttaller than the maximum width. Dimensions: H = 4.86.8µm; W = 4.0-5.0µm. Holotype: Pl.29, fig.15.
Paratype: Pl.29, fig.13. Type locality: TDP Site 2, near
Kilwa, Tanzania. Type level: Middle Eocene, Sample
TDP2-22-1, 62cm (Subzone NP15b). Occurrence:
NP15b-23; TDP Sites 1, 2, 6.
Lanternithus arcanus sp. nov.
Pl.29, figs 16-25, 30. Derivation of name: From arcanus,
meaning closed, referring to the closed central-area of this
holococcolith. Diagnosis: Medium-sized holococcolith,comprising several distinct crystallographic blocks thatchange appearance on rotation in XPL. At 0°, six blocks
are visible: four major quadrants, alternating dark andlight, delineated by axial sutures, and one small block ateach end. At 5°, the four quadrants are bright and a small
pore is visible in the centre. At 45°, the coccolith is brightand crossed by diagonal extinction lines. Differentiation:
Similar to L. minutus but with narrower central-area.
Dimensions: L = 4.6-5.5µm. Holotype: Pl.29, fig.16 (figs
17-20 same specimen). Paratype: Pl.29, fig.21 (figs 2224 same specimen). Type locality: TDP Site 2, near
Kilwa, Tanzania. Type level: Middle Eocene, Sample
TDP2-7-1, 38cm (Subzone NP15c). Occurrence: NP15bc; TDP Site 2, 6.
Lanternithus simplex sp. nov.
Pl.29, figs 26-29, 31-35; Pl.30, figs 1-5. Derivation of
name: From simplex, meaning plain or simple, referringto the relatively simple construction of this holococcolith.
Diagnosis: Medium-sized holococcolith, comprising several distinct crystallographic blocks. At 0°, four blocks arevisible, four major quadrants demarcated by dark extinction lines. There is a small pore visible at the centre of thecoccolith. Differentiation: Simpler in appearance thanother species of the genus, with fewer ‘crystallographically’-distinct blocks. Similar to L. arcanus but slightly
smaller, more broadly elliptical, and with a larger central-

40

Bown

area/pore. Dimensions: L = 4.6-4.9µm. Holotype: Pl.29,
fig.31 (figs 32-34 same specimen). Paratype: Pl.29,
fig.26 (figs 27-29 same specimen). Type locality: TDP
Site 10, Singino Hill, Tanzania. Type level: Upper
Paleocene, Sample TDP10-12-2, 26cm (Subzone NP9b).
Occurrence: NP9b-14b/15a; TDP Sites 2, 7B, 10.
Youngilithus gen. nov.
Type species: Youngilithus oblongatus sp. nov.
Derivation of name: After Dr. Jeremy Young (Natural
History Museum, London, UK), nannopalaeontologist.
Diagnosis: Geometrically-shaped, non-birefringent holococcoliths, typically possessing lateral rim spines andcentral-area bars.
Youngilithus arcaeformis sp. nov.
Pl.30, figs 6-8. Derivation of name: From arca(e), meaning box, chest or coffin, and formis, meaning in the shapeof, referring to the distinct outline of this holococcolith.
Diagnosis: A polygonal, medium-sized, non-birefringent
holococcolith with narrow rim spanned by diagonal crossbars. Rim coffin-shaped (like a diamond with flattenedends) and usually shows small, marginal projections.
Differentiation: Similar to O. brytika but with more geometric outline and with lateral rim spines. Dimensions: L= 4.3-5.3µm. Holotype: Pl.30, fig.6 (fig.7 same specimen). Paratype: Pl.30, fig.8. Type locality: TDP Site 2,near Kilwa, Tanzania. Type level: Middle Eocene,
Sample TDP2-15-1, 89cm (Subzone NP15b).
Occurrence: NP15b-c; TDP Site 2. Rare.
Youngilithus oblongatus sp. nov.
Pl.30, figs 9-15. Derivation of name: From oblongus,
meaning oblong, referring to the distinct outline of this
holococcolith. Diagnosis: Rectangular, medium-sized,
non-birefringent holococcolith with lateral rim projections. Sides of rectangle formed from narrow, crystallographically-distinct units, and some specimens have aninternal, transverse bar. Dimensions: L = 6.0-8.2µm; W =3.1-6.1µm. Holotype: Pl.30, fig.11 (figs 12, 13 same
specimen). Paratype: Pl.30, fig.9 (fig.10 same specimen). Type locality: TDP Site 2, near Kilwa, Tanzania.
Type level: Middle Eocene, Sample TDP2-15-1, 89cm
(Subzone NP15b). Occurrence: NP15b-c; TDP Sites 2, 6.
Youngilithus quadraeformis sp. nov.
Pl.30, figs 16-20. Derivation of name: From quadra(e),meaning square, and formis, meaning in the shape of,referring to the distinct shape of this holococcolith.
Diagnosis: Square, medium-sized, non-birefringent holococcolith with narrow rim bearing small, marginal projections, spanned by cross-bars parallel with sides.
Dimensions: L = 3.4-3.7µm. Holotype: Pl.30, fig.16(fig.17 same specimen). Paratype: Pl.30, fig.18 (figs 19,
20 same specimen). Type locality: TDP Site 2, near
Kilwa, Tanzania. Type level: Middle Eocene, Sample
TDP2-4-1, 50cm (Subzone NP15c). Occurrence: NP15c;

TDP Site 2.
Varolia gen. nov.
Type species: Varolia cistula sp. nov. Derivation of
name: After Dr. Osman Varol (Varol Research, UK),nannopalaeontologist. Diagnosis: Cavate, thin-walled,
box-like holococcoliths, usually seen in side view.
Varolia cistula sp. nov.
Pl.30, figs 21-25. Derivation of name: From cistula,meaning little box, referring to the distinct shape of this
holococcolith. Diagnosis: Small- to medium-sized, thinwalled, box-like structure with gently curved upper surface. Thin, birefringent walls comprise at least four crystallographically-distinct blocks. The structure broadens
distally from basal plate, is typically wider than it is highand may be circular in plan view (see Pl.30, fig.25).
Differentiation: Similar in overall structure to Varolia
gracilimura but usually not so high, and less domed.
Dimensions: H = 2.9-3.9µm; W = 4.3-4.7µm. Holotype:
Pl.30, fig.21 (fig.22 same specimen). Paratype: Pl.30,
fig.24. Type locality: TDP Site 1, near Kilwa, Tanzania.
Type level: Lower Oligocene, Sample TDP1-10-2, 76cm
(Zone NP23). Occurrence: NP23; TDP Sites 1, 6.
Varolia gracilimura sp. nov.
Pl.30, figs 26-30. Derivation of name: From Latin gracilis, meaning slender, and murus, meaning wall, referringto the narrow walls of this holococcolith. Diagnosis:
Medium-sized, thin-walled, dome-like structure. Thin,birefringent walls form proximal plate and domed uppersurface. Dome broadens distally from basal plate and is ofsimilar height and width, or taller. Differentiation:
Similar in overall structure to V. cistula but usually higher and domed. Dimensions: H = 3.5-5.5µm; W = 3.55.0µm. Holotype: Pl.30, fig.26 (fig.27 same specimen).
Paratype: Pl.30, fig.28 (fig.29 same specimen). Type
locality: TDP Site 4, near Ras Tipuli, Tanzania. Typelevel: Middle Eocene, Sample TDP4-5-1, 1cm (Zone
NP17). Occurrence: NP15b-17; TDP Sites 2, 4, 6.
Genus Semihololithus Perch-Nielsen, 1971
Used here for Palaeogene holococcoliths usually seen inside view, comprising a thick proximal plate, and spine orprocess, typically with a cavity or axial canal.
Semihololithus biscayae Perch-Nielsen, 1971
Pl.30, figs 31-35. Holococcoliths seen in side view, comprising thick, proximal plate and solid, domed, distal
process. Dimensions: H = 4.4-5.3µm; W = 4.4-6.2µm.
Occurrence: NP9b/10-10; TDP Sites 7A, 7B.
Semihololithus cf. S. biscayae Perch-Nielsen, 1971
Pl.31, figs 1-5. Similar to S. biscayae but considerably
smaller and with relatively larger central cavity.
Dimensions: H = 2.1-3.2µm; W = 3.0-4.5µm.
Occurrence: NP9b; TDP Site 10.

Palaeogene calcareous nannofossils...Tanzania

Semihololithus dimidius sp. nov.
Pl.31, figs 6-10. Derivation of name: From dimidius,
meaning divided in half, referring to the partitioned natureof this holococcolith. Diagnosis: Small holococcolith
seen in side view, comprising thin proximal plate andthin-walled, tapering distal process that surrounds central
cavity divided in half by narrow wall. Dimensions: H =2.4-2.8µm; W = 3.3-3.9µm. Holotype: Pl.31, fig.7 (figs 6,
8 same specimen). Paratype: Pl.31, fig.9. Type locality:
TDP Site 10, Singino Hill, Tanzania. Type level: Upper
Paleocene, Sample TDP10-40-3, 68cm (Subzone NP9b).
Occurrence: NP9b; TDP Site 10.
Semihololithus tentorium sp. nov.
Pl.31, figs 11-20. Derivation of name: From tentorium,
meaning tent, referring to the distinct shape of this holococcolith. Diagnosis: Medium-sized holococcolith seenin side view, comprising thin proximal plate, thick walls
and relatively thick-walled, rapidly tapering, cavate, distal process/spine. Dimensions: H = 4.6-5.6µm; W = 4.75.0µm. Holotype: Pl.31, fig.11 (figs 12, 13 same specimen). Paratypes: Pl.31, fig.16 (figs 17, 18 same specimen). Type locality: TDP Site 10, Singino Hill, Tanzania.
Type level: Upper Paleocene, Sample TDP10-40-3, 68cm
(Subzone NP9b). Occurrence: NP9b; TDP Site 10.
Semihololithus kanungoi sp. nov.
Pl.31, figs 21-25. Derivation of name: After Sudeep
Kanungo (UCL, UK), nannopalaeontologist. Diagnosis:
Small- to medium-sized, cavate holococcolith seen in side
view, comprising thin proximal plate, thick walls, andthin-walled, hollow, distal process/spine that tapers initially, then becomes parallel-sided. Dimensions: H = 3.65.8µm; W = 3.6-5.1µm. Holotype: Pl.31, fig.21 (figs 22,
23 same specimen). Paratype: Pl.31, fig.24. Type locality: TDP Site 7A, Kwamatola, Tanzania. Type level:
Lower Eocene, Sample TDP7A-62-1, 70cm (Zone NP10).
Occurrence: NP9b/10-10; TDP Sites 7A, 7B.
Daktylethra punctulata Gartner in Gartner & Bukry,
1969
Pl.31, figs 26-35. Holococcolith seen in side view, comprising thin, proximal plate and rim, and large, hollow,
perforate, domed distal process. The Tanzanian specimens
display some variability, particularly in distal process
shape, and are not identical to the type images, but are
deemed similar enough to warrant inclusion in thisspecies. Dimensions: H = 3.6-6.5µm; W = 3.6-7.7µm.
Occurrence: NP14b/15a-b; TDP Sites 2, 6. NP16-17(Gartner, 1971).
Zygrhablithus Deflandre, 1959
The most common Palaeogene holococcolith, and variable in morphology. The genus is divided here based on
details of the spine/process shape. I use Zygrhablithus
bijugatus bijugatus for coccoliths with tapering spines, Z.
bijugatus nolfii for those with short, squat spines and a

41

distinct lateral notch, and Z. bijugatus cornutus for spines
with prominent lateral projections. Unfortunately, theholotype of the principle species, Z. bijugatus, is a planview, and thus difficult to reconcile with the different sideviews. In plan view, the coccoliths are non-birefringent
and the central structure is figure-of-eight-shaped.
Zygrhablithus bijugatus bijugatus (Deflandre in
Deflandre & Fert, 1954) Deflandre, 1959
Pl.32, figs 1-10. Medium to large, spinose holococcolith,comprising rim and central process; spine has narrow,axial canal and tapers uniformly to a distal point or blunt
termination. Dimensions: H = 2.7-16.4µm; W = 3.26.1µm. Occurrence: NP9b-23; TDP Sites 1, 2, 3, 4, 6,
7A, 7B, 8, 10. Synonym: Semihololithus kerbayi PerchNielsen, 1971.
Zygrhablithus bijugatus (Deflandre in Deflandre & Fert,
1954) Deflandre, 1959 cornutus ssp. nov.
Pl.32, figs 11-15. Derivation of name: From cornutus,
meaning horned, referring to the distinct spine morphology of this holococcolith. Diagnosis: Medium-sized, spinose holococcolith, comprising rim and central process;spine relatively long, with narrow axial canal, and shortlateral protrusions or horns at its distal end (two in sideview). Dimensions: H = 7.7-7.8µm; W = 5.1-6.1µm.
Holotype: Pl.32, fig.11. Paratype: Pl.32, fig.12 (fig.13
same specimen). Type locality: TDP Site 1, near Kilwa,
Tanzania. Type level: Lower Oligocene, Sample TDP1-73, 75cm (Zone NP23). Occurrence: NP23; TDP Site 1.
Zygrhablithus cf. Z. bijugatus (Deflandre in Deflandre &Fert, 1954) Deflandre, 1959 cornutus ssp. nov.
Pl.32, figs 16-20. Like Z. bijugatus cornutus but withbroader, near-parallel-sided spine. Occurrence: NP15b;
Site TDP 2.
Zygrhablithus bijugatus (Deflandre in Deflandre & Fert,
1954) Deflandre, 1959 nolfii Steurbaut, 1990
Pl.32, figs 21-28. Small- to medium-sized, spinose holococcolith, comprising rim and central process; spine shortand broad (coccoliths typically wider than high), with
notch just above height of rim, and rather broad, axial
canal. Dimensions: H = 4.4-6.3µm; W = 5.1-7.6µm.
Occurrence: NP10-15b; TDP Sites 2, 3, 7A. Upper NP11
(Steurbaut, 1990).
Zygrhablithus cf. Z. bijugatus (Deflandre in Deflandre &Fert, 1954) Deflandre, 1959 nolfii Steurbaut, 1990
Pl.32, figs 29-30. Like Z. bijugatus nolfii but with smaller, more rounded spine that has a less pronounced notch.
Dimensions: H = 3.2-4.1µm; W = 4.6-4.9µm.
Occurrence: NP9b/10; TDP Site 7B.
Clathrolithus Deflandre in Deflandre & Fert, 1954
Applied here to unusual holococcoliths with non-coccolith morphology, comprising domed, perforate framework

42

Bown

(see electron micrographs in Gartner & Bukry, 1969).
Clathrolithus arenarius (Stradner, 1962) comb. nov.
Pl.33, figs 1-5. Basionym: Corannulus arenarius
Stradner, 1962, p.366, pl.1, figs 14-20; Sonderabdruck
aus den Verhandlungen der Geologischen Bundesanstalt,
2: 363-377. Remarks: Large (~9µm), non-birefringent,
elliptical holococcolith, comprising perforate frameworkwith large central pore and 9-13 marginal pores.
Occurrence: NP15b-17; TDP Sites 2, 4. Rare.
Clathrolithus ellipticus Deflandre in Deflandre & Fert,
1954
Pl.33, figs 6-23. Clathrolithus ellipticus andPeritrachelina ornata were described from the same
Lower Eocene sample by Deflandre (in Deflandre & Fert,
1954), and represent two different views of the same,rather strangely constructed, holococcolith (ostensiblyplan and side views, respectively). The holococcolith is a
non-birefringent, large (11-13µm), domed, perforate
structure that curves strongly in side view. In plan view,structure roughly elliptical and framework honey-comblike and pierced by 8-18 pores. It is often broken intofragments. Most of the specimens observed here are
more-coarsely constructed than the holotypes (of both
species) but I have applied the same name. Only specimens with much smaller pores were included in
Clathrolithus minutus. Occurrence: NP9b-15b; TDP
Sites 2, 3, 4, 6, 7A, 7B, 8, 10.
Clathrolithus minutus Bramlette & Sullivan, 1961
Pl.33, figs 24-25. Like Clathrolithus ellipticus but withgreater number of smaller perforations (~<0.5µm); notobserved in side view. Occurrence: NP9b; TDP Site 10.
Rare.
Clathrolithus joidesa (Bukry & Bramlette, 1968) comb.
nov.
Pl.33, figs 26-30. Basionym: Peritrachelina joidesa
Bukry & Bramlette, 1968, p.154, pl.2, fig.8; Tulane
Studies in Geology, 6: 149-155. Remarks: C-shaped nannoliths only observed in side view. Similar in appearance
to C. ellipticus but pores not visible. Occurrence: NP23;
TDP Site 1. Upper Eocene-Oligocene (Bukry &Bramlette, 1968).

stylifera (Pl.34, figs 16-22).
Braarudosphaera aff. B. bigelowii (Gran & Braarud,1935) Deflandre, 1947
Pl.34, figs 20-22
Braarudosphaera cf. B. hockwoldensis Black, 1973
Pl.34, figs 8, 13-15. Braarudosphaera with protruding
pentalith segments, first described from the Lower
Cretaceous. Used tentatively here due to large stratigraphic gap between observations. Occurrence: NP10-23;
TDP Sites 1, 2, 3, 7A. Rare. FO Upper Aptian (Black,1973).
Braarudosphaera stylifera Troelsen & Quadros, 1971
Pl.34, figs 18-19
Braarudosphaera aff. B. stylifera Troelsen & Quadros,
1971
Pl.34, figs 16-17
Micrantholithus discula (Bramlette & Riedel, 1954)
comb. nov.
Pl.34, figs 23-27. Basionym: Braarudosphaera discula
Bramlette & Riedel, 1954, p.394, pl.38, fig.7; J. Paleont.,
28: 385-403. Remarks: Simple, elevated Micrantholithus
morphology with rounded outline and elliptical sideviews. Occurrence: NP9b-15b; TDP Sites 2, 3, 7A, 7B,
8, 10.
Micrantholithus flos Deflandre in Deflandre & Fert,
1954
Pl.34, figs 28-29. Following the illustrations in Deflandre& Fert (1954), I use this name for simple Micrantholithus
morphologies with relatively straight edges. Comparable
to Micrantholithus hoschulzii (Reinhardt, 1966)
Thierstein, 1971, described from the Lower Cretaceous.
Cretaceous Micrantholithus species are not usually
recorded above the Aptian (Bown et al., 1998; Burnett,
1998), and thus the Palaeogene species observed herein
are considered to be separate taxa. Occurrence: NP15c23; TDP Sites 1, 2.
Micrantholithus crenulatus Bramlette & Sullivan, 1961
Pl.34, figs 30-32; Pl.35, figs 1-2. Like M. flos but withcrenulate edges. Occurrence: NP9b/10-11; TDP Sites 3,
7A, 7B.

6.4 Nannoliths
Family BRAARUDOSPHAERACEAE Deflandre,
1947
Braarudosphaera bigelowii (Gran & Braarud, 1935)
Deflandre, 1947
Pl.34, figs 1-7, 10, 11. Large variability in size (3.725.6µm), with larger forms having more-rounded apices.
Elevated forms and side views are named
Braarudosphaera aff. B. bigelowii or Braarudosphaera

Micrantholithus bulbosus Bouché, 1962
Pl.35, figs 3-5. Similar to M. flos but with raised ridges
around the sutures that widen at their ends. Occurrence:
NP14b/15a-15b; TDP Sites 2, 6.
Micrantholithus breviradiatus sp. nov.
Pl.35, figs 6-10. Derivation of name: From brevis, short,and radiatus, meaning ray, and referring to the outline ofthis pentalith. Diagnosis: Small to large Micrantholithus
with shallowly-indented sides and rounded apices.

Palaeogene calcareous nannofossils...Tanzania

Comparable to Micrantholithus obtusus Stradner, 1963,
described from the Lower Cretaceous. Dimensions: L =2.7-9.1µm. Holotype: Pl.35, fig.8. Paratype: Pl.35, fig.7.
Type locality: TDP Site 8, Singino Hill, Tanzania. Typelevel: Lower Eocene, Sample TDP8-5-1, 40cm (Zone
NP10). Occurrence: NP9b-11; TDP Sites 3, 7B, 8, 10.
Micrantholithus astrum sp. nov.
Pl.35, figs 11-15. Derivation of name: From astrum,
meaning a star, referring to the distinct outline of this pentalith. Diagnosis: Medium-sized Micrantholithus withdeeply indented sides and rounded apices. Similar to
Micrantholithus stellatus Aguado in Aguado et al., 1997,
described from the Lower Cretaceous. Rays are broader
than Micrantholithus aequalis Sullivan, 1964.
Dimensions: L = 6.7-10.8µm. Holotype: Pl.35, fig.14.
Paratype: Pl.35, fig.12. Type locality: TDP Site 2, Kilwa
Masoko, Tanzania. Type level: Middle Eocene, Sample
TDP2-22-1, 62cm (Subzone NP15b). Occurrence:
NP10-15b; TDP Sites 2, 3, 6, 7A, 7B.

43long rays. Height of pentalith results in ragged LM
appearance. Differentiation: Like M. attenuatus but witha higher morphology. Dimensions: L = 9.0-17.7µm.
Holotype: Pl.35, fig.34. Paratype: Pl.36, fig.1 (fig.2
same specimen). Type locality: TDP Site 4, near Ras
Tipuli, Tanzania. Type level: Middle Eocene, Sample
TDP4-4-1, 46cm (Zone NP17). Occurrence: NP11-23;
TDP Sites 1, 2, 3, 4, 6.
Pemma Klumpp, 1953
Pl.36, figs 13-26, 28-30. Pentaliths with a perforation ineach segment; often elevated, robust structures, commonly observed in side view. Occurrence: NP14b/15a-17;
TDP Sites 2, 4, 6.
Pemma papillatum Martini, 1959
Pl.36, figs 13-14, 30
Pemma basquense (Martini, 1959) Báldi-Beke, 1971
Pl.36, figs 15-19
Family DISCOASTERACEAE Tan, 1927

Micrantholithus pinguis Bramlette & Sullivan, 1961
Pl.35, figs 16-17. Similar to M. astrum but with more-elevated structure. Occurrence: NP10-15b; TDP Sites 2, 7A,
7B, 8.
Micrantholithus hebecuspis sp. nov.
Pl.35, figs 18-25. Derivation of name: From hebes,
blunt, and cuspis, meaning point, and referring to the distinct shape of this pentalith. Diagnosis: Large
Micrantholithus with deeply indented sides and blunt,flat-ended apices. Dimensions: L = 7.1-12.7µm.
Holotype: Pl.35, fig.21. Paratype: Pl.35, fig.22. Type
locality: TDP Site 3, Mpara Hill, Tanzania. Type level:
Lower Eocene, Sample TDP3-12-2, 27cm (Zone NP11).
Occurrence: NP11-15c; TDP Sites 2, 3.
Micrantholithus bramlettei Deflandre in Deflandre &Fert, 1954
Pl.35, figs 26-30; Pl.36, fig.31. General morphology like
Micrantholithus, ie. pointed rays (in this case with indented and notched sides), but segments joined along sutureswith Braarudosphaera-like orientation, i.e. they meet theouter edge on the sides, rather than at the points.
Occurrence: NP9b-11; TDP Sites 3, 7A, 7B, 8.
Micrantholithus attenuatus Bramlette & Sullivan, 1961
Pl.34, figs 9, 12; Pl.35, figs 31-33; Pl.36, fig.27. Stellate
Micrantholithus with deeply indented sides and gracile,long rays. Micrantholithus aequalis is similar but smaller.
Occurrence: NP9b/10-11; TDP Sites 3, 7A, 7B, 8.
Micrantholithus excelsus sp. nov.
Pl.35, figs 34-35; Pl.36, figs 1-4. Derivation of name:
From excelsus, meaning high, referring to the elevatedmorphology of this pentalith. Diagnosis: Large, elevatedMicrantholithus, with deeply indented sides and gracile,Five- to six-rayed discoasters
Discoaster mahmoudii Perch-Nielsen, 1981
Pl.37, figs 1-10; Pl.38, fig.1. Highly distinctive discoaster, usually with 5 or 6 tapering, free rays and a centralarea crossed by exceptionally high, inter-ray ridges thatform a stellate boss. Arms frequently broken off, leaving
a Catinaster-like central area. Occurrence: NP9b/10-10;
TDP Sites 7A, 7B. Rare specimens found in TDP 2(NP15) may be reworked (see below).
Discoaster cf. D. mahmoudii Perch-Nielsen, 1981
Pl.37, figs 11-15. Six- to 8-rayed discoasters always
observed obliquely due to a large, narrow spine/boss on
one side. Catinaster-like appearance reminiscent of D.
mahmoudii. Occurrence: NP15; Site TDP 2.
Discoaster saipanensis Bramlette & Riedel, 1954
Pl.37, fig.16
Discoaster sublodoensis Bramlette & Sullivan, 1961
Pl.37, fig.17
Discoaster tanii Bramlette & Riedel, 1954
Pl.37, figs 18-19
Discoaster martinii Stradner, 1959
Pl.37, fig.20
Discoaster nodifer (Bramlette & Riedel, 1954) Bukry,
1973
Pl.37, figs 23-25; Pl.38, fig.4. Discoaster stradneri Noël,1960 and Discoaster binodosus hirundus Martini, 1958
both have 7-rayed Discoaster nodifer specimens as theirholotypes. Here, I include 6-9-rayed forms in nodifer.
Occurrence: NP14b/15a-17; Site TDP 2, 4, 6.

44

Bown

Discoaster ornatus Bramlette & Wilcoxon, 1967 stat.
nov.
Pl.37, fig.26. Basionym: Discoaster tani ornatus
Bramlette & Wilcoxon, 1967, p.112, pl.7, fig.8; Tulane
Studies in Geology, 5: 93-131. Remarks: Morphology
considered distinct enough to warrant species status.
Discoaster distinctus Martini, 1958
Pl.37, figs 27-28. Five-rayed, stellate discoasters withheavily-noded, ray-tip bifurcations that resemble spanners. Identical to some of the drawings of Discoastergemmifer Stradner, 1961. Occurrence: NP14b/15a-c; Site
TDP 2.
Discoaster deflandrei Bramlette & Riedel, 1954
Pl.37, fig.29
Discoaster colletii (Parejas, 1934) Bersier, 1939
Pl.37, fig.30
Discoaster acutus sp. nov.
Pl.37, figs 31-34. Derivation of name: From acuo, meaning pointed, referring to the rays of this discoaster.
Diagnosis: Typically 6-rayed, stellate discoaster with relatively long, tapering, free rays, comparable in length tocentral-area width. Central area has inter-ray ridges andsmall but prominent central boss on one side. Rays lookrather ragged and sometimes appear to be asymmetricallyarranged. Differentiation: Similar to Discoaster araneus
Bukry, 1971 (7-9 rays) but with fewer, and more regularly-arranged, rays. Dimensions: L = 11.8µm. Holotype:
Pl.37, fig.33 (fig.34 same specimen). Paratype: Pl.37,
fig.31 (fig.32 same specimen). Type locality: TDP Site
7A, Kwamatola, Tanzania. Type level: Lower Eocene,
Sample TDP7A-62-1, 20cm (Zone NP10). Occurrence:
NP10-?11; TDP Sites 3?, 7A.
Discoaster sp.
Pl.38, figs 2-3. Six- to 8-rayed discoasters with long,curving, free rays that may be asymmetrically arranged.
Occurrence: NP9b-10; TDP Sites 7B, 10.
Multi-rayed discoasters
Discoaster megastypus (Bramlette & Sullivan, 1961)
Perch-Nielsen, 1984
Pl.38, figs 5-7
Discoaster mohleri Bramlette & Percival, 1971
Pl.38, figs 10-11
Discoaster lenticularis Bramlette & Sullivan, 1961
Pl.38, figs 12-13
Discoaster wemmelensis Achuthan & Stradner, 1969
Pl.38, figs 15-16
Discoaster multiradiatus Bramlette & Riedel, 1954
Pl.38, figs 14, 20-23
Discoaster salisburgensis Stradner, 1961
Pl.38, figs 24-28. Used in a broad sense here for multira-diate, rosette discoasters with prominent boss on one side
only. Occurrence: NP9b/10-10; TDP Sites 7A, 7B, 8.
Discoaster diastypus Bramlette & Sullivan, 1961
Pl.38, figs 29-33; Pl.39, figs 1, 6-8. Used here for medium to very large (7.1-19.1µm), multiradiate, rosette discoasters with prominent bosses on both sides and short,free rays that typically curve. Occurrence: NP10-11;
TDP Sites 3, 7A, 7B, 8.
Discoaster pacificus Haq, 1969
Pl.39, figs 2-5, 9. Like D. diastypus but fewer (8-10) andlonger, curving free rays. Occurrence: NP11; TDP Site 3.
Discoaster kuepperi Stradner, 1959
Pl.39, figs 10-16
Discoaster barbadiensis Tan, 1927
Pl.39, figs 17-19
Discoaster falcatus Bramlette & Sullivan, 1961
Pl.39, figs 20-25
Discoaster splendidus Martini, 1960
Pl.39, figs 26-29
Discoaster mediosus Bramlette & Sullivan, 1961
Pl.39, figs 30-34; Pl.40, figs 1-7. Eight to 10 near-parallelrays, with rounded to pointed tips (Bramlette & Sullivan,
1961) that radiate with little free length from large, circular central area. Many show inter-ray ridges, a low central
boss, and development of nodes towards ray-tips. In the
Tanzanian material, there is complete intergradation
between this species and Discoaster binodosus. The two
are distinguished here as follows: D. mediosus usually has
10 rays or more, with free rays less than half length ofcentral-area; D. binodosus usually has 8 rays with longer
free length, prominent lateral nodes and pointed ray-tips.
Occurrence: NP9b/10-10; TDP Sites 7A, 7B, 8.
Discoaster binodosus Martini, 1958
Pl.40, figs 8-15. Usually 8 rays with free ray length thatapproaches half diameter of central-area or greater,
prominent lateral nodes and pointed ray-tips.
Occurrence: NP10-15c; TDP Sites 2, 3, 7A, 8.
Family FASCICULITHACEAE Hay & Mohler, 1967
Fasciculithus aubertae Haq & Aubry, 1981
Pl.40, figs 16-17. Small (H = <3µm), gently tapering column, and visible fenestrae in XPL. Proximal and distal
surfaces gently concave and convex, respectively.
Occurrence: NP9b/10; TDP Sites 7A, 7B, 10.
Fasciculithus thomasii Perch-Nielsen, 1981
Pl.40, figs 18-20. Small to medium (H = 2.7-4.1µm), withtapering column, pointed apical termination and deeply
concave proximal surface. Fenestrae visible in XPL.
Occurrence: NP9b/10; TDP Sites 7A, 7B, 10.

Palaeogene calcareous nannofossils...Tanzania

Fasciculithus tympaniformis Hay & Mohler in Hay etal., 1967
Pl.40, figs 21-23. Used here for small- to medium-sized(H = 3.8-4.5µm) forms with gently tapering, or near-parallel-sided, column, small apical cycle, and smooth outline. The smoothness may be a diagenetic feature, inwhich case the species is a junior synonym of
Fasciculithus involutus. Occurrence: NP9b/10; TDP
Sites 7A, 7B, 10.
Fasciculithus involutus Bramlette & Sullivan, 1961
Pl.40, figs 24-27. Used here for small- to large-sized (H =3.5-7.6µm) forms, with gently tapering, or near-parallelsided, column, small apical cycle and visible fenestrae.
Occurrence: NP9b/10; TDP Sites 7A, 7B, 10.
Fasciculithus sidereus Bybell & Self-Trail, 1995
Pl.40, fig.28
Fasciculithus richardii Perch-Nielsen, 1971
Pl.40, figs 31-32
Fasciculithus tonii Perch-Nielsen, 1971
Pl.40, fig.33
Fasciculithus schaubii Hay & Mohler, 1967
Pl.40, figs 34-35
Family RHOMBOASTERACEAE fam. nov.
Type genus: Rhomboaster Bramlette & Sullivan, 1961.
Diagnosis: Nannoliths with rhombic and triradiate morphologies, and non-birefringent images in XPL.
Incorporating the genera Rhomboaster and Tribrachiatus.
Remarks: Rhomboaster and Tribrachiatus nannoliths
comprise an evolutionary lineage from the oldest, rhombic nannoliths (cuspis-type), through intermediate forms
with two superimposed triradiate cycles (bramletteitype), to the youngest, single-cycled triradiate forms(orthostylus-type). Bybell & Self-Trail (1995, 1997)
argued for the use of one genus only, whereas others haveretained both (e.g. Aubry, 1996). Both genera are used
here: Rhomboaster for nannoliths with three-dimensional,
rhombic to bicyclic, triradiate morphologies, andTribrachiatus for flatter morphologies with a single triradiate cycle.
Rhomboaster cuspis Bramlette & Sullivan, 1961
Pl.41, figs 1-20. Rhombic Rhomboaster nannoliths that
display variable morphology, in particular in the length ofextensions from the points of the rhomb. Bybell & SelfTrail (1995, 1997) considered the length of these extensions, and also the distinction between R. cuspis andRhomboaster bramlettei, to be a function of preservation(see also discussion in Wei and Zhong, 1996, and vonSalis et al., 1999). However, the relatively constantpreservation observed herein suggests that the differences
may be original, and therefore stratigraphically significant. Occurrence: NP9b/10-10; TDP Sites 7A, 7B, 8.
Rhomboaster bramlettei (Brönnimann & Stradner, 1960)
Bybell & Self-Trail, 1995

45

Pl.41, figs 21-35. Two symmetrically-offset and superimposed triradiate cycles. Three-dimensional but flatter thanR. cuspis. Occurrence: NP10; TDP Sites 7A, 7B, 8.
Tribrachiatus digitalis Aubry, 1996
Pl.42, figs 1-9. Single-cycled, triradiate forms, with long
ray-tip bifurcations. Rays in same plane and bifurcations
only slightly deviate from that plane. T. digitalis clearlyintergrades with Tribrachiatus orthostylus, as shown by
the transitional morphologies in Site TDP3 (Pl.42, figs 9,15), but the stratigraphic range recorded by Aubry (1996),
and used to define Subzone NP10b, appears to contradict
this ancestor/descendant relationship. The results here
indicate a rather younger range for this species and I apply
T. digitalis to Tribrachiatus nannoliths that have bifurcations that are deeply indented to around 25%, or more, of
the total arm length.
Tribrachiatus orthostylus Shamrai, 1963
Pl.42, figs 10-22. Large, single-cycled, triradiate nannoliths with little or no ray-end bifurcation (<25% of totalarm length).
Nannotetrina cristata (Martini, 1958) Perch-Nielsen,
1971
Pl.43, figs 1-9. Large, three-dimensional nannolith,
broadly cross-shaped, with arms that widen towards theirends. Somewhat comparable LM appearance toRhomboaster but probably no phylogenetic link.
Relationship with zygodiscids suggested by PerchNielsen (1985). Occurrence: NP14b/15a-15c; Site TDP
2.
Family SPHENOLITHACEAE Deflandre, 1952
Sphenolithus moriformis (Brönnimann & Stradner, 1960)
Bramlette & Wilcoxon, 1967
Pl.43, figs 10-12. Small- to medium-sized (H = 4-7µm),
non-spined sphenolith with domed upper surface.
Synonym: Sphenolithus primus Perch-Nielsen, 1971.
Sphenolithus acervus sp. nov.
Pl.43, figs 13-19. Derivation of name: From acervus,
meaning a heap or mass, referring to the coarsely-constructed, robust appearance of this sphenolith. Diagnosis:
Large (>8.0µm), globular, coarsely-constructed sphenolith without spine. Differentiation: Like S. moriformis
but larger (>8.0µm). Dimensions: W = 8.5-11.6µm.
Holotype: Pl.42, fig.15. Paratype: Pl.42, fig.19. Type
locality: TDP Site 3, Mpara Hill, Tanzania. Type level:
Lower Eocene, Sample TDP3-19-3, 4cm (Zone upper
NP10/11). Occurrence: NP9b-11; TDP Sites 3, 8, 7A,
7B, 10. Similar forms seen rarely in NP15b, TDP Site 6.
Sphenolithus editus Perch-Nielsen in Perch-Nielsen etal., 1978
Pl.43, figs 20-24. Small- to medium-sized (H = 4.5-

46

Bown

7.8µm), with short spine, broad triangular shape (dartshaped), and wide base in which lower quadrants dominate. Compound spine dark at 0°. Occurrence: NP11;
TDP Site 3.
Sphenolithus spiniger Bukry, 1971
Pl.43, figs 25-29. Small- to medium-sized (H = 4.09.4µm), with short spine, narrow, triangular (dart-shaped)
shape. Lower quadrants largest and compound spine dark
at 0°. Differentiation: Similar to S. editus but with narrower base. Occurrence: NP14b/15a-c; TDP Site 2.
Sphenolithus anarrhopus Bukry & Bramlette, 1969
Pl.43, figs 30-34; Pl.44, figs 1-5. Medium-sized (H = 6.29.2µm), with short to relatively long spine that is slightly
asymmetrical and dark at 0°. Square-shaped base withnear-equidimensional quadrants and deep spine insertion.
Differentiation: Similar to Sphenolithus radians but
spine completely dark at 0°. Base broader and squarer
than Sphenolithus villae. Occurrence: NP9b-10; TDP
Sites 7A, 7B, 10.
Sphenolithus conspicuus Martini, 1976
Pl.44, figs 6-10. Medium-sized (H = 5.0-6.7µm), narrowsphenolith with tall spine that is dark at 0° and conspicuously bright at 45°. Tall base with long upper quadrantsthat form part of spine. Differentiation: Similar to
Sphenolithus villae but smaller, with longer upper quadrant extensions and shorter lower quadrants. Occurrence:
NP11; TDP Site 3.
Sphenolithus villae sp. nov.
Pl.44, figs 11-24. Derivation of name: After Dr. Giuliana
Villa (Univ. of Parma, Italy), nannopalaeontologist.
Diagnosis: Large (H = 7.5-19.8µm), narrow sphenolithwith tall spine that is dark at 0°. Relatively tall base, withroughly equidimensional upper and lower quadrants.
Spine indents deeply into upper quadrants, appears to be
monocrystalline, and is brightest at 45°. Differentiation:
Comparable in general morphology to the Miocene
Sphenolithus belemnos, however S. villae is larger, morerobustly constructed, with blockier spine and base.
Dimensions: H = 7.5-19.8µm. Holotype: Pl.44, fig.19(fig.18 same specimen). Paratypes: Pl.44, fig.24 (fig.23
same specimen); Pl.44, fig.11 (fig.12 same specimen).
Type locality: TDP Site 3, Mpara Hill, Tanzania. Typelevel: Lower Eocene, Sample TDP3-4-3, 52cm (Zone
NP11). Occurrence: NP11; TDP Site 3.
Sphenolithus radians Deflandre in Grassé, 1952
Pl.44, figs 25-32. Medium- to large-sized (H = 6.612.1µm), with tall, compound spine and square-shapedbase with equidimensional quadrants. Spine dark but visible at 0° and characterised by median suture line; at 45°,the spine is brightest. Narrow spine endings, up to 3x
length of main sphenolith, have been rarely observed, i.e.
up to 38µm. Occurrence: NP11-17; TDP Sites 2, 3, 4, 6.

Sphenolithus pseudoradians Bramlette & Wilcoxon,
1967
Pl.44, figs 33-34
Sphenolithus furcatolithoides Locker, 1967
Pl.45, figs 1-5. Small (base H = 3.6-4.8µm), with twolong spines that are bright at 0° (dark at 45°), extending
from upper quadrants (up to 20µm in length). Base dark
and inconspicuous at 45°. Occurrence: NP15b-c; TDP
Sites 2, 6.
Sphenolithus cuniculus sp. nov.
Pl.45, figs 6-10. Derivation of name: From cuniculus,
meaning rabbit, referring to the rabbit-ear-like upper
quadrants/spine of this sphenolith. Diagnosis: Medium tolarge sphenolith, with short lower quadrants and longupper quadrants that bifurcate. Differentiation: Similar to
S. furcatolithoides but lower quadrants shorter and upper
quadrants broader: conceivably a preservational variant.
Dimensions: H = 5.2-~14.0µm. Holotype: Pl.45, fig.6.
Paratype: Pl.45, fig.7 (fig.8 same specimen). Type locality: TDP Site 2, Kilwa Masoko, Tanzania. Type level:
Middle Eocene, Sample TDP2-2-1, 15cm (Subzone
NP15c). Occurrence: NP15c-?23; TDP Sites 1, 2.
Sphenolithus obtusus Bukry, 1971
Pl.45, figs 11-20. Medium to large (H = 5.1-11.3µm), withtall spine and low base, comprising single cycle of triangular quadrants. Spine dark at 0° and brightest at 45°.
Most spines monocrystalline, but some duocrystalline;
this may be orientation-related. Occurrence: NP17; TDP
Site 4.
Sphenolithus conicus Bukry, 1971
Pl.45, figs 21-25. Large (H = 6.2-8.4µm), with short,blunt spine and broad, robust base. Lower quadrants large
and spine dark at 0°. Occurrence: Lower Oligocene(NP23); TDP Site 6.
Sphenolithus predistentus Bramlette & Wilcoxon, 1967
Pl.45, figs 26-35. Small- to medium-sized (H = 3.47.5µm, excluding bifurcations), with tall, narrow, bifurcating spine and very short lower quadrants. Occurrence:
NP23; TDP Sites 1, 6. NP17-24 (Perch-Nielsen, 1985).
Family LAPIDEACASSACEAE Bown & Young, 1997
Lapideacassis glans? Black, 1971
Pl.46, figs 1-2. Very rare and may be reworked.
Incertae sedis nannoliths
Biantholithus flosculus sp. nov.
Pl.46, figs 3-7. Derivation of name: From flosculus,
meaning little flower, referring to petaloid morphology ofthis nannolith. Diagnosis: Medium-sized, circular,rosette-shaped nannolith with 11-16 radial rays. Weakly

Palaeogene calcareous nannofossils...Tanzania

birefringent in XPL. Differentiation: Similar to rosette
discoasters but with birefringence in XPL. Similar toother Biantholithus species but more numerous and withthinner rays. Dimensions: W = 4.5-6.3µm. Holotype:
Pl.46, fig.6 (fig.7 same specimen). Paratypes: Pl.46, fig.
4; Pl.45, fig.5. Type locality: TDP Site 10, Singino Hill,
Tanzania. Type level: Upper Paleocene, Sample TDP1035-3, 58cm (Subzone NP9b). Occurrence: NP9b; TDP
Site 10.
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Acknowledgements
Thanks to the TDP team, the heroic reviewers, Laurel Bybell
and Tim Bralower, and editor, Jackie Lees.

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Bown

Plate 1Prinsiaceae: Toweius, Prinsius, Hornibrookina

Palaeogene calcareous nannofossils...Tanzania

Plate 2
Noelaerhabdaceae: Cyclicargolithus, Reticulofenestra

51

52

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Plate 3
Noelaerhabdaceae: Reticulofenestra; Coccolithaceae: Coccolithus

Palaeogene calcareous nannofossils...Tanzania

Plate 4
Coccolithaceae: Coccolithus, Ericsonia

53

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Plate 5
Coccolithaceae: Campylosphaera, Cruciplacolithus

Palaeogene calcareous nannofossils...Tanzania

Plate 6
Coccolithaceae: Cruciplacolithus, Bramletteius, Chiasmolithus

55

56

Bown

Plate 7
Coccolithaceae: Chiasmolithus, Cruciplacolithus, Clausicoccus

Palaeogene calcareous nannofossils...Tanzania

Plate 8
Calcidiscaceae: Coronocyclus, Umbilicosphaera?, Calcidiscus?

57

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Plate 9Calcidiscaceae: Calcidiscus?; Incertae sedis placoliths: Pedinocyclus

Palaeogene calcareous nannofossils...Tanzania

Plate 10
Incertae sedis placoliths: Hayella, Pedinocyclus, Ellipsolithus, etc.

59

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Bown

Plate 11
Chiastozygaceae; Helicosphaeraceae: Helicosphaera

Palaeogene calcareous nannofossils...Tanzania

Plate 12
Helicosphaeraceae: Helicosphaera

61

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Plate 13
Helicosphaeraceae: Helicosphaera

Palaeogene calcareous nannofossils...Tanzania

Plate 14
Pontosphaeraceae: Pontosphaera

63

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Bown

Plate 15
Pontosphaeraceae: Pontosphaera

Palaeogene calcareous nannofossils...Tanzania

Plate 16
Pontosphaeraceae: Pontosphaera, Scyphosphaera

65

66

Bown

Plate 17
Pontosphaeraceae: Scyphosphaera

Palaeogene calcareous nannofossils...Tanzania

Plate 18
Zygodiscaceae: Lophodolithus, Zygodiscus

67

68

Bown

Plate 19
Zygodiscaceae: Zygodiscus, Neochiastozygus

Palaeogene calcareous nannofossils...Tanzania

69

Plate 20
Zygodiscaceae; Calciosoleniaceae; Syracosphaeraceae; Incertae sedis

70

Bown

Plate 21
Rhabdosphaeraceae: Blackites, B. gladius & B. morionum groups

Palaeogene calcareous nannofossils...Tanzania

Plate 22
Rhabdosphaeraceae: Blackites, B. morionum group

71

72

Bown

Plate 23
Rhabdosphaeraceae: Blackites, B. morionum & B. herculesii groups

Palaeogene calcareous nannofossils...Tanzania

Plate 24
Rhabdosphaeraceae: Blackites, B. herculesii group

73

74

Bown

Plate 25
Rhabdosphaeraceae: Blackites

Palaeogene calcareous nannofossils...Tanzania

Plate 26
Rhabdosphaeraceae: Blackites

75

76

Bown

Plate 27
Holococcoliths: Holodiscolithus

Palaeogene calcareous nannofossils...Tanzania

Plate 28
Holococcol.: Holodiscolithus, Orthozygus, Corannulus, Lanternithus

77

78

Bown

Plate 29
Holococcoliths: Lanternithus

Palaeogene calcareous nannofossils...Tanzania

Plate 30
Holococcoliths: Lanternithus, Youngilithus, Varolia, Semihololithus

79

80

Bown

Plate 31
Holococcoliths: Semihololithus, Daktylethra

Palaeogene calcareous nannofossils...Tanzania

Plate 32
Holococcoliths: Zygrhablithus

81

82

Bown

Plate 33
Holococcoliths: Clathrolithus

Palaeogene calcareous nannofossils...Tanzania

Plate 34
Nannoliths: Braarudosphaeraceae

83

84

Bown

Plate 35
Nannoliths: Braarudosphaeraceae

Palaeogene calcareous nannofossils...Tanzania

Plate 36
Nannoliths: Braarudosphaeraceae

85

86

Bown

Plate 37
Nannoliths: Discoasteraceae

Palaeogene calcareous nannofossils...Tanzania

Plate 38
Nannoliths: Discoasteraceae

87

88

Bown

Plate 39
Nannoliths: Discoasteraceae

Palaeogene calcareous nannofossils...Tanzania

Plate 40
Nannoliths: Discoasteraceae, Fasciculithaceae

89

90

Bown

Plate 41
Nannoliths: Rhomboasteraceae

Palaeogene calcareous nannofossils...Tanzania

Plate 42
Nannoliths: Rhomboasteraceae

91

92

Bown

Plate 43
Nannoliths: Nannotetrina, Sphenolithaceae

Palaeogene calcareous nannofossils...Tanzania

Plate 44
Nannoliths: Sphenolithaceae

93

94

Bown

Plate 45
Nannoliths: Sphenolithaceae

Palaeogene calcareous nannofossils...Tanzania

Plate 46
Nannoliths, ascidians, calcispheres95